basic setup corresponding to file import
First version
accidentals supported
Basic durations supported
tuplets supported
Merge branch 'master' of https://github.com/wbsoft/frescobaldi into export-musicxml

Conflicts:
	frescobaldi_app/menu.py
reverting export_colored_html
Merge branch 'master' of https://github.com/wbsoft/frescobaldi into export-musicxml
ties supported
handle different file structures
setting initial bar attributes per part
dots supported
fixing bar attributes at start
Merge branch 'master' of https://github.com/wbsoft/frescobaldi into export-musicxml
Merge pull request #252 from PeterBjuhr/export-musicxml

Basic musicXML export