1. Check for entity addition success in spawn_item implementation
2. Check for success in item_drop callback, so that the player
doesn't lose the item if they are outside bounds and try to drop it.
3. When existing player joins game, check that their position is inside
map bounds. If not, set their position to the return value of findSpawnPos().
4. Make findSpawnPos() respect the border

2 fixes a lua crash if a player drops an item outside map bounds.
3 fixes an assertion crash if a player leaves when being outside map bounds,
and then rejoins.

Use std::queue instead of std::set, we don't need such a heavy container.
Don't convert position to int to convert it back to float in the next function.

The legacy code added in commit

d879a539 - "Add minetest.swap_node"

for sending the whole mapblock to older clients on the case of a node
modification with swap_node, had the problem that the block chosen to be
sent to the client was referenced with node coordinates and not with
block coordinates, resulting in getting the wrong block sent to the client.

  * 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.

src/server.cpp
src/emerge.cpp

-> Remove the SendableMediaAnnouncement struct
-> Forge the packet directly in the m_media loop, spare one loop and the construction of a vector
-> Use preincrement to spare iterator copies

Enable the server to request the client to reconnect.

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

Use wide_to_utf8 and utf8_to_wide instead of wide_to_narrow and narrow_to_wide at almost all places.
Only exceptions: test functions for narrow conversion, and chat, which is done in a separate commit.

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

Its a possible mistake to log in to a server with twice the same name.
Before, it triggered a server wide error message, now it logs to actionstream.

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.

NodeResolver name lists now belong to the NodeResolver object instead of
the associated NodeDefManager.  In addition to minimizing unnecessary
abstraction and overhead, this move permits NodeResolvers to look up nodes
that they had previously set pending for resolution.  So far, this
functionality has been used in the case of schematics for
serialization/deserialization.

If the player is disconnected while Lua API is doing a l_punch call, for example, the playersao is NULL and the server crash. Fix it.

Also set the packet size at creation not when pushing rawString, no functional change

This greatly increases crafting performance, especially in worlds with many mods.

Approved by @kwolekr.

Introduces a hash-type-layered fall-through mechanism, where every layer specifies one hash algorithm,
and the "deeper the fall", the more collisions to expect for the algorithm. One Craft definition
only resides at one layer, which improves speed for lower layers (and a complete fail), due to most
craft definitions residing at high layers.

Due to the fall-through design, the undocumented behaviour that later craft recipes
override older ones had to be weaked up a bit, but craft recipes with the same hash and layer
will still override.

Approved by: @kwoelkr

Move debug streams to log.cpp|h

Move GUI-related globals to clientlauncher

Move g_settings and g_settings_path to settings.cpp|h

Move g_menuclouds to clouds.cpp|h

Move g_profiler to profiler.cpp|h

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

  * Combine client and server man pages.
  * Update unit test options and available databases in man page.
  * Add `--worldname` to man page.
  * Fix a bunch of places where `"Minetest"` was used directly instead of `PROJECT_NAME`.
  * Disable server build by default on all operating systems.
  * Make `ENABLE_FREETYPE` not fail if FreeType isn't found.
  * Enable LevelDB, Redis, and FreeType detection by default.
  * Remove the `VERSION_PATCH_ORIG` hack.
  * Add option to search for and use system JSONCPP.
  * Remove broken LuaJIT version detection.
  * Rename `DISABLE_LUAJIT` to `ENABLE_LUAJIT`.
  * Rename `minetest_*` variables in `version.{h,cpp}` to `g_*`.
  * Clean up style of CMake files.

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

This was a regression introduced by f6e4c5d9 .

Replace it with an errorstream + assert for server

This throw can be trigger by LuaError exception or ConnectionBindFailed exception in the following functions:
* EmergeThread::Thread()
* ScriptApiEnv::environment_Step()
* ScriptApiEnv::player_event()
* ServerThread::Thread()

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