Changes to stafftext.ui

The staff text ui is now a fixed size. The Aeolus stop list has a
customised palette now and all stops are the same size. The font family
for the Aelous stop list has been changed from Serif Dejavu to the
system font used for the other button text in the dialogue, which Qt
Designer is reporting as MS Shell Dlg 2 The UI size is now a little over
800 x 600.

This is the prelude for more changes to the Aeolus Stoplist section of stafftext.ui