Send program changes for armed tracks at record

Fix for bug #1356 "Wrong instrument when recording on multiple 
tracks/channels".  This mimics the behavior of 11.11.42 which would
send program changes for armed tracks when the user hit record.  This
makes it possible to record from multiple MIDI controllers and hear
the appropriate instruments from each controller.


git-svn-id: http://svn.code.sf.net/p/rosegarden/code/trunk/rosegarden@13248 cf6a83e7-f017-4305-b0b3-678bde24f230