* Also change some std::list to std::vector for ClientMap::renderMap
* Remove disabled code in ClientMap::renderMap, disabled since a long time

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

- Fixes particle draworder
- Fixes nodehighlighting

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

Conf.example: Update mgv5 mapgen params
Mgv7: Lava caves only below -256

* Also remove dead code Map::unloadUnusedData which is dead since a long time

* This permit to cleanup the player checking loop

* setTimeOfDaySpeed already lock a mutex when modify the value, we don't need to lock all environment.
* add a fine grain lock for getTimeOfDay and setTimeOfDay to solve environment multithread modifications on this value

* 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.

* Ensure converted string is NUL terminated
* Restore logic to that used prior to 9e2a9b55

This reverts commit c09d026f.

Add find_surface_nodes_in_area LUA call which permit to only get the nodes which touch air. This permit to massively improve performance for mods like plantlife

Directely or indirectly optimises the following functions:

* MapBlockMesh::MapBlockMesh
* MapBlockMesh::getTileInfo
* MapBlockMesh::makeFastFace
* MapBlockMesh::getSmoothLightCombined

wrapDegrees() (renamed to modulo360f)
wrapDegrees_0_360
wrapDegrees_180

Minor errors were present in previous versions; see issue #2328

Rebased by Zeno- (conflict in lua_api.txt)

Linux distributions prefer to link against a shared version of the Irrlicht
engine instead of using embedded code copies of the same. Search for this
shared version first and use that but fall back to the static version if it
does not exist.

This also fixes https://github.com/minetest/minetest/issues/2163