GLMixer Code

Updated behavior after QtFatal message to match new log management mode.

work in progress for a 1.8 splash

GUI cosmetics

Added preset Mask to show how to use a video as dynamic mask (using
lumakey)

BugFix: restore fading parameters of video after reloading videofile

Windows DOS implementation of GLMixerApp instance listing

BugFix: alpha fading of session switcher could be sensitive to texture
previously bound.

BugFix: rendering source update of ffglplugin on change of texture index
(change of mode or after initial creation)

Re-implementation of single instance mechanism and re-implementation of
log file management. Now correctly detecting crash logs upon application
start.

compilation fix