List-like arrow for MIDI import operations
update windows build to Qt 5.1.1
add missing dll on windows
more fixes for spanners & import
Merge pull request #454 from trig-ger/midi_arrow

List-like arrow for MIDI import operations
fix measure search when instrument is hidden
fix #22451: MuseScore should make it impossible to load styles made in previous version
create beams in MusicXML import even if stem direction is not explicit
When, for a change in the cross-measure value setting, notes change from stemmed to stemless (or vice versa), stems are not properly removed or added.
Breves are vertically misaligned and in different horiz. positions when 'up-stemmed' and 'down-stemmed' (assuming the had a stem).

Fixed by adding the Note::HEAD_BREVIS case when centring note heads.
Merge pull request #456 from mgavioli/cross-measure_values_stems

Cross-measure values: fix stemmed-stemless shape changes
Merge pull request #457 from mgavioli/Brevis_vert_align

Brevis note heads vertical alignment