extend StaffType for alternative notations. create StaffTypeTemplate class for customizable, saveable StaffTypes.  create StaffTypeTemplates Dialog.
properly disable widgets in STT dialog when no templates exist.  clean up old comments in other parts of code.
start work on dotted lines and fix bug in alternative absstep involving incorrect octaves
provide proper note drag behavior for alternative notemapping.  fix bug with accidentals.
add basic preview box to Stafftype Template Dialog