trackmaker v0.3.0

the number three! this one's a lot closer to what i'd expect the complete release's workflow to look like

features:

• selections!
  • when in view mode, drag to select events in an area. currently works with notes and gear shifts
  • or press ctrl+a to select everything
• copying and pasting!
  • you can press ctrl+c to copy some events, or ctrl+x to cut them, then ctrl+v to paste
  • this works with your system clipboard, so you can paste it to other places aswell
• mirroring!
  • check Edit for the mirroring options
  • lets you mirror horizontally, vertically, or both

fixes:

• fixes with event sorting
• fix very rare sort crash
• quantization when writing xdrvs should now FINALLY be good and work and function

full changes here: v0.2.2...v0.3.0