stafftext.ui update

Finally managed to sort this out! Aeolus stop list buttons are now of a
uniform colour and Tremulants have green text and couplers have red.
Had to resort to hacking the file in Notepad++ to get the width and
height back to the original values -Qt Designer inisits on increasing
the width to 1134 and then won't let you change it.
stafftext.ui fix

Forgot to set the active tab back to 0 :)
Merge pull request #479 from ChurchOrganist/stafftext.ui-update

Stafftext.ui update