'Change Instrument' should set trackName accordingly

STR:
1. Run the 'Create Score' plugin
2. Press "i" to open 'Create Instruments' dialog
3. Discard the 'Create Instrument' dialog, Right-click a measure, select 'Staff Properties...' from the context menu
4. Change instrument from 'Piano' to 'Harp'
5. Go back to Step 2.

Actual results: the name of the stave, which is identical with the trackName, remains "Piano".

Expected results: the name of the stave has become "Harp".

MuseScore r2796 on Ubuntu 9.10 with Qt 4.6.1

I haven't set priority to "minor" because there is presently no other way to modify trackName property as to edit the XML file directly.