Remove circular buffer and adjust usage.
Replace auto_ptr with scope guard and adjust usage.
Remove util.d
First step for removing _render from Texture: subTexture and copy don't need the _render method anymore. Furthermore they are now const.

Texture::getMemory accepts now an optional parameter for the memory so
that it prefers to use that instead of GC memory.
Move _render from Texture to Sprite/Spritesheet/Text
Use C memory instead of GC in Image.saveToFile
Simplify shared and unique_ptr. free method in Font, Renderer, RenderTexture and Surface use now release instead of dissolve.
Add construct in Allocator and remove empty line in Window.
Fix collideWith in Spritesheet and overhaul blend usage.
Adapted version number.