* Moved the GLEnable and GLDisable structures from opengl_gui_graphics.cpp to fife_opengl.h as they may prove to be useful elsewhere. * Fixed the color mask definitions in fife_stdint.h * Added the nextPow2() function to calculate the nearest (greater) power of 2 * Removed a bunch of re-definitions of RGB masks * Modified GLImage to only generate one "texture chunk". I hope this makes better use of memory and speeds things up a hair * Made use of the GLEnable structure when clearing the screen