libOBS will simply forget to unlock a mutex if you set the boundary size to zero, resulting in the filters dialog for that source simply getting stuck. Why video rendering can affect the audio filter dialogs is a question for another time, but it's best to just accept it and move on.
Previously this would not do anything correctly, as the call to obs_source_get_flags does not return anything for most sources. Instead obs_source_get_output_flags should be used to verify that we actually have a video or audio capable source to work with.
obs::source_tracker allows us to do more over more versions of OBS Studio, so we are able to enumerate any and all Sources, Scenes and Transitions that weren't created private. If we were to rely on libOBS for this, we would need to limit ourselves to version 23 or higher, but with this we can go very far back - as far back as the global event system was fully supported.
The number of files in the source directory was a little bit much and just made file naming more complex than it had to be. Therefore all files were moved into subdirectories where it matters.
Filters now reside in source/filters/, Sources in source/sources/, OBS Wrappers in obs/, OBS GS Wrappers in obs/gs/, Transitions will reside in source/transitions, Graphics Helpers will be in gfx/.
