This is part 2 for 5f084cd9

Other improvements:

* Use the defined ItemGroupList when used
* make Client::checkPrivilege const
* inline some trivial functions
* Add ActiveObjectMap typedef
* Add SettingsEntries typedef

* This permit to improve performance on C++11 builds
* use some existing typedefs in tools maps
* minor code style changes

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

Remove uses of std::map.
Make sure we use ContentFeatures reference not value.
Original commit by gregorycu.

The fallback vector is in case 'wallmounted to dir' is nil due
to voxelmanip placing a wallmounted node without resetting a
pre-existing param2 value that is out-of-range for wallmounted.
The fallback vector corresponds to param2 = 0.

Adds a flag to forceload_block which lets you turn off persistence for
that forceload.

'getSpawnLevelAtPoint()' did not account for disabled mountains, it
was possible to be spawned in mid-air where a mountain surface would
have been.

Avoid check for river area if rivers are disabled.

Fixes #4493.

Re-add documentation of noise parameter formats.
Re-add 'mgv5_np_ground' noise parameters in group format.
Both these were deleted through auto-generation of conf.example.
Add note to builtin/mainmenu/dlg_settings_advanced.lua that this
documentation must be preserved.

The libraries updated in this commit were built with a set of scripts:
	https://gist.github.com/sfan5/780c24313c164d34634e18677683b9a3
Building new library versions or just using a different MinGW version
is now way easier. This means Windows builds no longer need to use
ancient library versions just because nobody knows how to build them.

This allows you to use an stdcall zlib (zlib1.dll instead of zlibwapi.dll)
when building Minetest for win32.

This commit fixes #4516, though note that this will gradually fix MapBlocks
as they are used/modified and thus re-serialized.

Fix a typo pointed out by @thecow275.

Also, use the deprecated notification system which respects the
deprecated_lua_api_handling setting.

Add 'core.LIGHT_MAX = 14' to builtin/game/constants.lua with the intention
to replace misplaced 'default.LIGHT_MAX = 14' in Minetest Game.
Add comment in light.h requiring the constant be changed in both places.
Add lighting bug warning to note in lua_api.txt.
There are hundreds of mod uses of 15 which causes a lighting bug.

Maximum is 14.
A value of 15 (reserved for direct sunlight) causes a lighting bug.

Inverts the given channels of the base image.
Mode may contain the characters "r", "g", "b", "a".
Only the channels that are mentioned in the mode string will be inverted.

In lua_api.txt, make clear that 'place on' and 'spawn by' can be lists.

Adds CMakeLists.txt include to fix this issue:

$ cmake . -DBUILD_SERVER=TRUE -DBUILD_CLIENT=FALSE \
   -DCMAKE_BUILD_TYPE=Release -DENABLE_CURL=TRUE -DENABLE_CURSES=FALSE \
   -DENABLE_FREETYPE=TRUE -DENABLE_GETTEXT=FALSE \
   -DENABLE_POSTGRESQL=FALSE -DENABLE_SOUND=FALSE -DENABLE_LUAJIT=TRUE \
   -DIRRLICHT_SOURCE_DIR=$HOME/irrlicht-1.8.4 -LH
...
CMake Error at src/CMakeLists.txt:339 (check_library_exists):
  Unknown CMake command "check_library_exists".
...

This snuck in with the meshoptions patch and accidentally kills
degrotate plants. Thanks to @hybriddog for finding this.