Publication of devel version 20140412

Written for ffDiaporama by domledom on 2014-04-12

Publication of a new devel version of the future ffDiaporama version 2.2

It contains a bug fix for new "master volume" feature and 2 new enhancement :
-Improves error message when encoding fails due to bad filename
-Adds a keyboard shortcut with the space bar to start or pause the preview player

And in addition, the removal of "deprecated" when using the new 2.2 version of ffmpeg