Define new IceCat source and document new helper (if any).
As for now previous version of GNU IceCat was hosted at,
http://devel.trisquel.info/repos/packages/icecat/
This has changed, and there is allegedly a new development on IceCat build.
app-install-data-ubuntu
Keep in mind add package changes to app-install-data-ubuntu: !211 (diffs)
External resources: