Simplified pickup speed randomisation
Entities handle chunks properly again

* Entities properly handle chunks
* Changed EntityStatus enums to be less shouty
Rewrote redstone powering to use power levels
Added asserts for proper game state.

This is to help hunt #889.
Mobs rotation
Merge pull request #896 from axisd/master

Mobs rotation
Implemented weighted pressure plates
Compile fix?
Prefabs can have per-piece per-placement weights.

Fixes #753.
Also upgraded NetherFortPrefabs to lates Gallery contents.
Added Prefab initializers to SELFTEST code.
Added new AI rules

+ Added new AI rules handling cacti and large heights
* Fixed cIniFile not recognising comments in cIniFile::ReadFile()
* Fixed users.ini not being properly generated
* Changed all instances of (int)floor(GetPosXXX()) to POSXXX_TOINT
Added area flooring.

Fixes #743.
Merge pull request #891 from mc-server/fixes

Fixes to redstone & general
Removed unsupported C++11 features.
Added performance test of the nether fort generator.