Fixed new line at end of some files
Changed Game namespace

 * Game, GameBehavior and my TestBehavior are now in the Pathfinder.Game namespace
 * All other classes are now simply under the Pathfinder namespace
Moved data classes in the Data namespace
Begun work on the Gui class
Added vertex color to the buffer
Added simple shaders for the gui
Fixed the line ending at end of shaders
Added a Rectangle drawing method in the Gui class

But for unknown reasons, the rectangle is only black...
With hard-coded color, it works???
Changed from vertex color to uniform color

 * Removed the Color component from the Buffer
 * Adjusted the Gui shader
 * Modified the Gui class
Added Texture2D class

Will be tested later ;)