Version 3.1.0

• Support for "old style" multiple measure rests (@rettinghaus)
• Support for note@vel and dynamics@val in MusicXML import (@earboxer)
• Support for multiRest@loc (@rettinghaus)
• Support for mNum@fontsize (@rettinghaus)
• Support for accidental-mark in MusicXML import (@rettinghaus)
• Support for double-stemmed beams (@eNote-GmbH)
• Improved barline rendition (@rettinghaus)
• Improved cross-staff notation with multiple layers
• Python Package Index (PyPI) distribution (@musicEnfanthen and @alastair)
• Option --footer extended with 'always' value to show footer with --adjust-page-height