Initial support for percussive staffs, possibly some noteheads used here will change
A little refactoring and some support for simile markings
Support for tuplets and double bar simile markings in GPX files
Refactoring and improving playback on GPX format - improvements to importing percussion still need to be made (drumset)
Guitar Pro implementation split up, support also for ties, grace notes, slides and other minor articulations.
Merge pull request #1058 from jpirie/22604-slides

Slides functionality, split up Guitar Pro implementation, grace/simile marking support in GP6