don't implode voices of different rhythms

as this it can lead to data loss.
On imploding staves it could lead to some incorrectness, but as the old
staves are still there, this can get spotted and fixed.
hide navigator by default
fix crash when opening scores with 0 measure (old templates)
Fix 40901: Midi remote control Augmentation dot doesn't work
fix #37986: lupdate doesn't like forward declaration enums... see http://www.qtcentre.org/threads/59673-lupdate-fails-to-detect-context-for-class-in-namespace
Merge pull request #1516 from rtega/404-new-feature

Fix 40901: Midi remote control Augmentation dot doesn't work
Merge pull request #1507 from Jojo-Schmitz/implode

don't implode chords of unequal duration
Merge pull request #1 from musescore/master

Add a redo button in the Midi Remote Control