This fixes #1573

main.cpp rework * Move ClientLauncher class to a dedicated file * ClientLauncher now owns print_video_modes and speed_tests functions (they are only called by him) * Move GameParams to shared/gameparams.h because it's shared between server and client and launcher need to know it * Move InputHandlers class to client/inputhandler.h * Cleanup includes

https://forum.minetest.net/viewtopic.php?f=6&t=11201
Fixed this bug.

No functionnal change

Fixes warning:
src/lua/src/loslib.c:60: Warning: the use of `tmpnam' is dangerous, better use `mkstemp'

Don't permit to open inventory is playerCAO isn't present. This prevent to open an empty inventory at player load. ok @zeno-

* Increase performance (client)
* Avoid changing a global value to solve a local problem

This reverts commit d25ff8fd.

* Increase performance (client)
* Avoid changing a global value to solve a local problem

Minetest fails to build on GNU/Hurd due to a name clash with OSX/Apple,
both are defining the __MACH__ keyword. This commit fixes the issue.

Before patch, function consumes up to ~8% of the main server loop. After, ~0% (below level of 2 places of significance)

Also simplify wget steps and apt-get install zlib1g-dev libjsoncpp-dev

* 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

Conf.example: Add mgv7 cave1, cave2 noiseparams
Mgv7: Make skipping of mountain code relative to y=0 not water level
Mountain noise offset now -0.6 to compensate
Tune chance of large caves