Implementation of Shader GLSL code source; basically a source with an ImageFilter that contains GLSL code. Connected so Shader Editor (like clone sources).
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.
Enable playing and seeking into a timeline on a media player that loaded an image. Timeline sets a duration (end) and is saved/loaded. Add a gstreamer imagefreeze element in the pipeline to simulate a playable stream. Distinction must be made between 'isImage' (what was loaded) and 'singleFrame' (what is in the pipeline). GUI is added and customized with menu and dialog.
Major changes in ImGuiVisitor (all image filtering and ImageProcessingShader), new imGuiToolkit ComboIcon (replacing previous ComboIcon widget), new icons,
All Stream report failure with logs, read in InfoVisitor for Sources. ImGuiVisitor for Sources also detect failure of source and its stream.
Cleanup of unused includes and functions.