* build & render terrain
* apply vignette effect during postprocessing
Merge branch 'master' into explorer

Conflicts:
	explorer/shared/explorer.c
* calculate chunks bboxes and do not render invisible chunks
* use tiles from texture atlases
* calculate normals
* basic lightning
* generate terrain height using trigonometric functions
* re-enabled fps indicator
* fixed compilation issues
+ added android client for explorer
Merge branch 'master' into explorer
Merge branch 'master' into explorer
Merge branch 'master' into explorer
Merge branch 'master' into explorer
Merge branch 'master' into fire
+ added Android makefile
+ added sky shader
Merge branch 'master' into explorer
* updated cmake build script
Merge branch 'master' into explorer
Merge branch 'master' into explorer
+ added new project 'fire'
Merge branch 'explorer' into fire