Mouse: the WindowHandle is set by the RenderSystem now after creating the render window
Mouse: the cursor position is now obtained using win32 to get nice relative client window coordinates
Mouse: SetPosition handled using win32 now
Color: fixed some issues and implemented some missing methods
TestCenter: refactoring (moved all ConvertEquals-Methods to the new AssertHelper)
DataFactory: extended by normalized random floats
TestCenter: all Color tests are green now