* 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