Key signature change and clef change don't stop at section break

1. New score
2. Add some section breaks
3. Change key signature or clef, before a section break

Expected result: the sections following the changed one remain unchanged, i.e. keep their clef and key sig

Actual result: the sections following the changed one have their key sig and clef changed

Support for the expected result: time sigs only affect the curent section.