Added cubemap editor to IDE material editor, added LightCube shader to the default pack, fixed cubemap bindings in GLSL, changed the way cubemaps are save in the material file, added cubemap selector in the material editor
Shader programs are now referenced by paths not names, will be loaded if not a current resource when loading shader, changed the default material files to reflect the new changes
Added clipboard support on linux using X11.

We're still using SDL1.2, but now some functions use X11, so if we every fully switch to X11, we can keep at least some of the code.

Courtesy of http://www.libsdl.org/projects/scrap/, which was gratefully released into the public domain.