fix #8924: native support for slash notation
fix #39456: double click drum icon enters wrong segment/voice
fix #39476: corruption on entry of drum note onto segment with no element in voice 1
fix #39466: initially selected drum not active
add support for file update on musescore.com
support 404 not found for get scores
update test files
Merge pull request #1463 from MarcSabatella/drum-entry-bugs

Drum entry bugs
Merge pull request #1460 from MarcSabatella/slash-notation

fix #8924: native support for slash notation
fix #20783: add section breaks to joined scores

and line and page breaks too...