GLMixer Code

Bugs fix for GLSL Shadertoy editor
- edit option context-reactive in context menu
- unlink editor when plugin changed (could be improved)

Shadertoy Plugin implementation : saving and loading in XML glm file,
options and help in GUI,

Implement reset of Shadertoy code + bugfix.

Implementation of ShaderToy GUI (Code editor with lineCount, actions of
buttons)

Continuing the implementation of ShaderToy FreeFrame plugin:
- changed functions for adding a new FFGL plugin to return pointer to
FFGLPluginSource
- Fixed mechanisms for initialization of FFGLPlugin
- fixed GUI for GLSL code editor

Working implementation of Shadertoy plugin with Freeframe 1.6 under
Linux. Still a lot to do :
GLSL code editor is buggy
Properties not synched
Code is not saved

Implementation of Shadertoy plugin with Freeframe mechanisms
- changed files for compilation of FFGLPluginInstance
- added DLL communication for code get and set

On-going implementation of opengl plugin with Shadertoy and Freeframe

Draft implementation of FreeFrameFragmentCodePlugin

Draft implementation of GUI for GLSL Fragment Code plugin