Changed Mixer Load behavior at init, detect change of version and do not load settings if different, show About Vimix after change of version, fixed initial position of windows at first run.
Initial implementation of Text Source, displaying free text or subtitle file. support for Pango font description and formatting tags via gstreamer textoverlay plugin. Saving and loading in XML, GUI for creation (in patterns) and for editing.
As in update of Mixer manager, failed sources are managed in update of SessionSources. RenderSources that fail are re-created. Attach/Detach/Attached of sources functions is unified between Session and Mixer.
2 new callbacks (PlayFastForward, PlaySpeed), modified Seek callback to take target time in seconds (instead of ratio of duration). Integrating this in Input Mapping GUI and Session saving.
When a source in a session fails, it is not anymore deleted after update; the Mixer keeps it in the session but detaches it from the scene. This way the user can access the failed source in the navigator (listed in RED), and Replace the source. The Replacement of source is available for any source. The source visitor does not skip a visit if the source failed.
