Upgrade packages for Sencha Cmd 4.0.1.
Update for use with latest version of VexFlow.

The fact that the VexFlow build system switched from SCons to Rake meant
that the Rondo hooks into the SCons build would no longer work. Rather
than requiring Ruby and friends for a Rake build, a Node script parses
the VexFlow sources through Esprima, and generates the necessary build
symbols to be integrated directly into the Sencha Cmd compilation.

This also required some small bugfixes, as Tutti.Theory was no longer
being initialized by the Vex.Flow.Music superclass, and as some VexFlow
components require a VexFlow rendering context to draw, rather than a
plain HTML5 2D context as before.