Release/0.2

* More code cleanup & bug-fixes.
* Improved mesh optimization (http://www.int6.org/development/voxeliq-engine/improved-mesh-optimization/)
* Added unit tests for engine.
* Implemented a basic & buggy console & commands subsystem.
* Implemented a very primitive blocky sky & clouds.
* Improved logging & configuration facilities.
* Implemented platform manager that can identify running platform & frameworks.
* Added vsync & fixed timesteps options to config.ini.
* Log targets are now also configured in config.ini now.
* Added an engine.log file log-target.
* Fixed a bug where chunks in cache-range were not lightened as expected.
* Added cache-range checks.
* Improved Chunk's and Block's string representation.
* Fixed issue #18 where view-range value was incorrectly used when calculating cache width and height. Instead cache-range had to be used and fixed so.
* Fixed Chunk.FastSetBlockAt() so that minus world coordinates also work. ChunkCache.GetChunk is also fixed for minus values. Player is now spawned at 0,0.
* Moved chunk statistics calculation to ChunkCache.Draw() - finally the values are preserved, which eventually fixes the chunk debug graph bugs.
* Added chunk removal queue debug-graph.
* Fixed a tiny capture mouse & mouse visibility bug.
* Moved ini-file based config-classes from Engine to Client project. Engine is now free of both Nini reference and the ini file itself. The actual game can do what-ever he wants when he supplies parameters to EngineConfig.
* The Engine ctor() will now throw an exception when additional instances created (Discussed in issue #43).