... though in a small cycle with each other, by moving RealtimeEffectManager to
new files, which remain in the big component.
Net loss of 1, the big component now has 27 files
... New files, but (almost) empty; don't use the global variable gAudioIO,
but use one of two accessor function names (which are the same function for
now).
AudioIOBase will have fewer dependencies than AudioIO -- in particular, no
dependency on tracks.
It won't include StartStream. It will contain functions to query the
present state of streams, and device capabilities.
... freeing 15 files from the big strongly connected component:
ImportFFmpeg & ODDecodeFFMpegTask (still in a cycle of two)
ImportFLAC
ImportGStreamer
ImportLOF
ImportMIDI
ImportMP3
ImportOGG
ImportPCM
ImportQT
ProjectFileManager
ProjectFSCK
ProjectManager
ProjectSelectionManager
ODDecodeFlacTask
And eight header files in src/import are deleted.
This breaks a lot of cycles because Import, which is still in the big component,
no longer includes ImportLOF, which recursively uses ProjectManager. A
registration system for the subclasses of ImportFileHandle allows that
recursion without the cyclic compilation dependencies.
... leaving AutoRecovery as a lower-level file, to be used by ProjectHistory
for auto-save, and not including ProjectManager.
The new file floats to a high level of the graph, but AutoRecovery.cpp
remains in the big strongly connected component.
... Generalizing what was first done at 280e8d9 for certain menu command
handlers.
Allow core data structures to host data attached by other code, on which it
need have no compilation or link dependencies.
... which makes Project.cpp a bit less dependent on some details of other
classes
This puts Tags.cpp back into the big strongly connected component of the
dependency graph. That will be remedied later when Project.cpp becomes a
low-level file
