Direct3D 9 Texture Retrieval
Implements graphics_get_texture_rgba for Direct3D9 effectively
implementing all sprite_save/background_save functions for the system.
Implements graphics_duplicate_texture
Implements graphics_replace_alpha_from_texture
Update copyright
Merge pull request #660 from RobertBColton/master

Direct3D 9 Textures.
Doesn't break GL1 or GL3.