Add Mlt::Deque::peek() (opengl branch).
Add mlt_image_glsl and _glsl_texture (opengl branch).
Add consumer-thread-started and -stopped events (opengl branch).
Add the new opengl module (opengl branch).
Let loader producer use new GLSL normalizing filters (opengl branch).
Add qglsl multi consumer (opengl branch).
Let melt and xml producer use qglsl consumer (opengl branch).
Fix syntax error in mlt++ symbol version script.
Cleanup some logging from work in opengl branch.
Fix crash when stopping xgl consumer.