minor improvement of UI

• upgrade to abc2svg 1.5.14 ( Crash on some cases of ties since 1.5.6)
• let "play" call "render" before playing if necessary
• now use green animation (flying notes) for progress indicator

Improved dropbox handling

Changes

• improved handling of dropbox 8bb3043

Improve Dropbox Handling

Changes

• improved handling of dropbox 8bb3043