Copperbox revision 3209.
Work towards a global metrical timeline. Both Ableton Live and Garage Band have metrical time lines - graphically it seems a good abstraction for synchronizing tracks.
If I add it properly to Majalan (currently it is just a standalone module under test) I'll have to remove BPM from the Context. BPM will still be accessible to individual event lists but it will be read-only and derived from the global timeline.