Fix/Remove stale/empty modcallback functions in script_properties that caused infinite modcallbacks on non-existent field changes that occur when no sources are yet defined. eg: as in a new OBS setup/config.

Fixed Settings Overrides that sometimes did not reset across scenes/shows properly. This affected the visibility of the Text source sometimes not showing across scenes. Updated the script and a few minor updates/cleanups in user guide and locale text and tooltips. Setup downloadable demo source zip file and viewable demo/test video at https://spyratech.com enabling a user to reproduce their own version of the same demo/test video. May be useful for initial learning and understanding of this software.

Updated to Add the Flags feature to the ScenesList for individualized show settings.

Initial Release