- When the remove source tool icon is clicked, it will now remove the
source from the scene.
- Fixed a bug where the scene item removal callback would add the scene
item to the list instead of removing it.
- Changed AddSourcePopup to AddSourcePopupMenu. Name actually confused
me once despite being the writer, so it was clearly a bad name.
Sources can now be added to scenes via user interface. It's a little
convoluted because everything has to work through OBS signals to ensure
that plugins/etc can modify the scenes/sources exernally.
Also, when switching scenes, it will properly list sources for the
scene you changed to.
