Added Fragment Shader support +

- Added: RAGE::Graphics.getOpenGLVersion()
- Added: RAGE::Graphics.getGLSLVersion()
- If boot.rb does not exist a message is displayed.
- Changed conf.rb. If conf.rb does not exist default configuration is
loaded.
- Changed RAGE.configure. Now accepts a hash value representing game
configuration.
- Added: RAGE::Shader class - OpenGL fragment shaders using GLSL
- Added: RAGE::Graphics.setMaximizedWindow(truefalseval)
- Added: RAGE::Graphics.setShader(shader)
- Added: RAGE::Graphics.getDisplayModes(),
RAGE::Graphics.setMousePosition(x, y),
RAGE::Graphics.setMouseBitmap(bitmap, focusX, focusY),
RAGE::Graphics.setMouseCursor(cursorIndex),
RAGE::Graphics.setMouseGrab(truefalseval)
Merge branch 'master' of https://github.com/ArekX/RAGE