shortcuts to optionboxes

concerning toolwindows/optionboxes:
- now the shortcuts are very windows-oriented (F9, F10, etc). On a mac those do not work.
- a simulare issue: under the menu "musescore" i see "preferences… " with the typical mac-shortcut "cmd+,", but greyed out. Under edit there is the real preferences option.

Yoris
working on a Macbook, Snow Leopard 10.6.2, using the dutch version of MuseScore, version 0.9.5, revision 2012