tweak Smart Mode to be more like Mixbus. Smart mode is just a modifier on Object...

tweak Smart Mode to be more like Mixbus.  Smart mode is just a modifier on Object mode which provides Range selection in the top half of the waveform.  probably lots of corner cases to clear up before its all over, but at least we can use Mixbus as a consistent target rather than making it all up again.

git-svn-id: svn://localhost/ardour2/branches/3.0@13551 d708f5d6-7413-0410-9779-e7cbd77b26cf