updates jquery and jquery ui

we now pull jQuery directly from jquery's CDN instead of google because
google serves slightly outdated versions under the /1/ branch

The updated smoothness theme currently breaks compression. Haven't
figured out why, yet.
added (failing) test case for broken jquery ui compression
fix single line comments in CSS compression

double slashes in url() always have to be ignored
updated jquery-migrate to v1.2.1
strip sourcemaps after update
fixed online comment stripping
strip sourcemaps in CSS and JS #601

source maps are invalid for our dispatched sources and may even cause
problems. this makes sure any sourcemap declarations are stripped from
the output
Merge pull request #586 from splitbrain/jqueryupdate

JQuery Update
Merge pull request #616 from splitbrain/stripsourcemaps

strip sourcemaps in CSS and JS #601