GLMixer Code

Creation of the OpenGL test widget for User Preference Dialog: allows
testing FBO Blit and PBO support.

Implementation of Automatic device detection in the Video4Linux camera
plugin.

Fixed Plugin Video4Linux.

Fixed OSX C++11 compilation warnings

Explicit requirement for GL_ARB_pixel_buffer_object (not only
GL_EXT_pixel_buffer_object) : the ARB extension is required for
GL_PIXEL_UNPACK_BUFFER.

Also testing GL_EXT_framebuffer_multisample for the Frame Buffer Blit.

CMake for FreeFrameFFPlay plugin (was missing).

Fixed implementation for insertion of source (problem with previous
commit).

BUGFix: resolved the issue of "Not enough space to insert the source
into the stack" when creating large number of sources (e.g. drop files).
Now a depth is correctly computed for a new source when hitting the
MAX_DEPTH_LAYER, and if necessary all sources are re-distributed
uniformly on the depth axis to make room for new sources.

Fixed implementation of SVG source. Incrementation of XML file version to
1.2.