Enable python tooling in Eclipse, clean up SCons build.
Add support for JSB2 auto-generation.

Used to supply auto-completion in the Spket plugin for Eclipse. Apps
should supply a `jsb.file` config parameter to indicate the path of the
generated JSB file, which is created (or updated) when running the 
command `sencha app refresh` for the given app.
Fix javascript errors in Rondo Mobile.

Some namespace and file paths needed to be adjusted, and using regular
class overrides for proxy configs on models didn't work.
Update note duration icons.

The icons now come from an icon font, as is recommended for Sencha
Touch 2.2.1, and are based on the newly-released (and open-source) font
Bravura from Steinberg. The derivative icon font "Bravina" is created
via IcoMoon (http://icomoon.io/).
Ignore intermediate files for CSS theme.