- now loading can be from any image format - added IntColor struct for precise pixel operations
- rewrote old C-style casts to new ..._cast<> - corrected some dangerous casts - added -Wold-style-cast to compile flags
- added CImage class for loading/saving images and a simple test for it - added libpng library to build - added Gfx::Texture struct - updated the Gfx::CDevice interface to include new features - implemented the new features in Gfx::CGLDevice