-fixed shaders for GL2
-added Entity selection tool
-throw out tools from "Demo" window to "Tools" window
-change ComboBox to Tabs for Tools
-Added more verbose tips
-Improved and fixed BrickBreaker collisions
-fixed simple DUB issue
-Added some more math functions
-fixed many memory leaks
-added AABB and BVHTree support to collision.d
*BVHTree has only incrementally adding entities implemented by now (and bad BottomUp algorithm)
*ECS Systems use two trees, one for static and one for dynamic entities, dynamic BVH is builded every frame from scratch by now
-BrickBreaker now uses BVHTree to collision detection
*balls only use tree for checks (they aren't adding to tree)
-fixed bug leading to crash
-added 'dot' function to vector math
-fixed Circle tool rendering
-fixed some potentiall memory leaks
-added 'collision' module which now separates ShootGrid from SpaceInvaders demo
-separate some systems from demos to 'basic' module to better demos functionality sharing
-slow down snake
-added new graphics
-BrickBreaker demo now works (without blocks breaking and with bugged collision detection)
-some bug fixes
