v0.6.1

• fix end-of-chart crash on preview mode
• timing event rendering has been redone to prepare for future changes
• zoomed out highlight lanes now scale properly
• allow playback of charts with no song
• fix 20ths not being saved right
• minor epsilon floating point fixes (should reduce the amount of duplicate notes, lost notes, etc type issues)

full changes: v0.6.0...v0.6.1