Update .ts translation files
Pull out Composition::isInstrumentRecording()
These have been applied as [r15125] through [r15130]. I also ran appstream-util validate and fixed the errors it identified. Those changes are in [r15131]. Please review.
amw2: Implement Show Audio Submasters
amw2: Implement Show Audio/Synth Faders
amw2: Remove Show Plugin Buttons feature
appdata: Fix errors per appstream-util validate
Update installation location of appstream metadata