Also remove some unused parameters/functions

Added the following chat coreside features
* Chat messages length limit
* Message rate limiting
* Message rate kicking

Note:
* handleChat now takes RemotePlayer pointer instead of u16 to remove useless
  lookups

Adds the particle option `collision_removal = bool`

Some particles are hard to use right now since they either go through
solid blocks (without collision detection), and with collision
detection enabled they (e.g. raindrops) would just stop dead on the
floor and sit there until they expire, or worse, scrape along a wall
or ceiling.

We can solve the problem by adding a boolean flag that tells the
particle to be removed if it ever collides with something. This will
make it easier to add rain that doesn't fall through your roof or stick
on the top of it. Or clouds and smoke that don't go through trees.

Particles that collide with this flag are marked expired
unconditionally, causing them to be treated like normal expired
particles and cleaned up normally.

Documentation is adjusted accordingly.

An added bonus of this patch is that particles can potentially collide
many times with nodes, and this reduces the amount of collisions to 1
(max), which may end up reducing particle load on the client.

Rebased by Zeno (2016-04-2016)

Fix regression of commit

5e507c98 "Add server side ncurses terminal"

which allowed all players, even those without a shout priv, to chat.

Fixes #3362.

Comply with line limit.

This adds a chat console the server owner can use for administration
or to talk with players.
It runs in its own thread, which makes the user interface immune to
the server's lag, behaving just like a client, except timeout.
As it uses the same console code as the f10 console, things like nick
completion or a scroll buffer basically come for free.
The terminal itself is written in a general way so that adding a
client version later on is just about implementing an interface.

Fatal errors are printed after the console exists and the ncurses
terminal buffer gets cleaned up with endwin(), so that the error still
remains visible.

The server owner can chose their username their entered text will
have in chat and where players can send PMs to.
Once the username is secured with a password to prevent anybody to
take over the server, the owner can execute admin tasks over the
console.

This change includes a contribution by @kahrl who has improved ncurses
library detection.

It isn't possible to use atomic operations for floats, so don't use them there.

Having a lock is good out of other reasons too, because this way the float time
and the integer time both match, and can't get different values in a race,
e.g. when two setTimeofDay() get executed simultaneously.

Use this macro to disallow copying of an object using the assignment
operator or copy constructor.  This catches otherwise silent-but-deadly
mistakes such as "ServerMap map = env->getMap();" at compile time.

If so desired, it is still possible to copy a class, but it now requires
an explicit call to memcpy or std::copy.

-> Put access to time variables under the time lock.
-> Merge both time locks, there is no point to have two locks.
-> Fix the lock being released too early in Environment::setTimeOfDay
-> Add serverside getter so that you don't have to get
	the environment if you only have the server

  * Rename everything.
    * Strip J prefix.
    * Change UpperCamelCase functions to lowerCamelCase.
  * Remove global (!) semaphore count mutex on OSX.
  * Remove semaphore count getter (unused, unsafe, depended on internal
    API functions on Windows, and used a hack on OSX).
  * Add `Atomic<type>`.
  * Make `Thread` handle thread names.
  * Add support for C++11 multi-threading.
  * Combine pthread and win32 sources.
  * Remove `ThreadStarted` (unused, unneeded).
  * Move some includes from the headers to the sources.
  * Move all of `Event` into its header (allows inlining with no new includes).
  * Make `Event` use `Semaphore` (except on Windows).
  * Move some porting functions into `Thread`.
  * Integrate logging with `Thread`.
  * Add threading test.

Enable the server to request the client to reconnect.

This can be done with the now extended minetest.request_shutdown([reason], [reconnect]) setting.

ObjectRef:
get_properties
get_armor_groups
get_animation
get_attach
get_bone_position

Players:
get_physics_override
hud_get_hotbar_itemcount
hud_get_hotbar_image
hud_get_hotbar_selected_image
get_sky
get_day_night_ratio
get_local_animation
get_eye_offset

Global:
minetest.get_gen_notify
minetest.get_noiseparams

Due to compatibility concerns, this is temporarily disabled.

Adds everything needed for SRP (and everything works too),
but still deactivated, as protocol v25 init packets aren't final yet.
Can be activated by changing the LATEST_PROTOCOL_VERSION header to 25
inside networkprotocol.h.

Also fix std::logic_error when server::DenyAccess() is used with only two arguments.

Approved by: @kwoelkr

Because we get a Buffer<u8> from ConnectionEvent, don't convert it to SharedBuffer<u8> and return it to Server/Client::Receive which will convert it to NetworkPacket
Instead, put the Buffer<u8> directly to NetworkPacket and return it to packet processing
This remove a long existing memory copy
Also check the packet size directly into Connection::Receive instead of packet processing

Don't send an InventoryAction at each setInventoryModified, we only need one SendInventory per inventory modification

Client doesn't like to receive multiples SendInventory for one action, this can trigger glitches on clients (sometimes due to incorrect UDP packet ordering due to UDP protocol)

This fix issue #2544

Fix a little regression on SendActiveObjectMessages which send all TOCLIENT_ACTIVE_OBJECT_MESSAGES as reliable

* TOSERVER_INIT and TOCLIENT_INIT renamed to _LEGACY
* TOSERVER_PASSWORD merged from dev-0.5, can use protocol v24 and v25
* TOCLIENT_ACCESS_DENIED merged from dev-0.5, can use protocol v24 and v25, with normalized strings an a custom id for custom errors
* new TOSERVER_INIT packet only send MT version, supported compressions, protocols and serialization, this permit to rework everything later without break the _INIT packet
* new TOSERVER_AUTH packet which auth the client
* new TOCLIENT_HELLO packet which send server serialization version atm
* new TOCLIENT_AUTH_ACCEPTED which is send when TOCLIENT_AUTH was okay. After this packet, the client load datas from servers, like after TOCLIENT_INIT_LEGACY packet

Rename some packet and handlers to <packet>_Legacy name for compat layer between new network changes and old network clients

Server.cpp Use std::list instead of std::vector for playSound, fillMediaCache, sendRequestedMedia, sendMediaAnnouncement and related functions

Server::AsyncRunStep: buffered_messages now uses std::vector instead of std::list. * sendRemoveNode and sendAddNodes are also converted as a side effect

Performance improvement: Use std::list instead of std::vector for request_media, Server::getModNames, Environment::m_simple_objects.
* Also remove unused Server::m_modspaths

* This permit to cleanup the player checking loop

* Call UpdateCrafting into SendInventory because this functions is only called before SendInventory
* Use Player* instead of peer_id for UpdateCrafting because SendInventory already has the Player* pointer, then don't loop for searching Player* per peer_id
* m_env_mutex don't need to be used with this modification because it's already locked before the calls

Send Player HP when setHP (or a setHP caller) is called instead of looping and testing the state change.

NetworkPacket.cpp:
* Remove some deprecated functions, we must use streaming interface
* m_data converted from u8* to std::vector<u8>
* Add an exporter to forge packet to Connection object
* implement operator << std::wstring. n
* implement operator << std::string
* dynamic resize when write packet content.
* fix string writing and performances.
* create ServerCommandFactory, used by client to get useful informations about packet processing (sending).
  * Reliability
  * Transmit channel
* Implement putRawString for some ugly char (_INIT packet), and use it.
* Many packet read and write migrated
* Implement oldForgePacket to interface writing with current connection
* fix U8/char/bool writing
* fix string writing and performances.
* add some missing functions
* Use v3s16 read instead of reading x,y,z separately
* Add irr::video::SColor support into packets
* Add some missing handlers
* Add a template function to increase offset
* Throw a serialization error on packet reading (must be improved)

PacketFactories:
* Create ServerCommandFactory, used by client to get useful informations about packet processing (sending).
* Create ClientCommandFactory, used by server to get useful informations about packet processing (sending).

Client.cpp:
* implement NetworkPacket ::Send interface.
* Move packet handlers to a dedicated file
* Remove Client::Send(SharedBuffer)

Server.cpp:
* implement NetworkPacket ::Send interface.
* Rewrite all packets using NetworkPacket
* Move packet handlers to a dedicated file
* Remove Server::Send(SharedBuffer)

ClientIface.cpp:
* Remove sendToAll(SharedBuffer<u8>)

Connection.hpp rework:
* Remove duplicate include
* Remove duplicate negation
* Remove a useless variable
* Improve code performance by using a m_peers_list instead of scanning m_peers map
* Remove Connection::Send(SharedBuffer)
* Fix useafterfree into NetworkPacket Sending
* Remove unused Connection::sendToAll

Test.cpp:
* Remove dead code
* Update tests to use NetworkPackets

Misc:
* add new wrappers to Send packets in client, using NetworkPacket
* Add NetworkPacket methods for Connection
* coding style fix
* dead code since changes cleanup
* Use v3s16 read instead of reading x,y,z separately in some packets
* Use different files to handle packets received by client and server
* Cleanup: Remove useless includes

ok @Zeno-
Tested by @Zeno- @VanessaE and @nerzhul on running servers

* Move networkcode to a dedicated directory
* Rename clientserver.h to network/networkprotocol.h (Better name) and sanitize some includes
* Create object NetworkPacket
  * It stores command (opcode) and data separated
  * It also stores peer_id
  * Data reading can be done by using a streaming interface
* Change packet routing analysis
  * Remove old conditional analysis
  * Now uses function pointed analysis and add connection state ({Client,Server}::handlers)
  * Connection state permit to categorize condition to handle before analyze packets
  * Create a handler for depreciated messages, instead of duplicating code