Compress the CSS in css2js.js, by removing comments & indentation

The file webodf.css is currently more or less directly converted into a string by css2js.js. Including the license header, all other comments and the indentation.

Based on heuristics and my little CSS syntax knowledge (so please better check) I propose to do some simple compression when creating the string. Spares some 5K bytes on webodf.js

Name | Size Before | Size After
--------|----------|-----
webodf/webodf.css.js| 16288 | 10929
webodf/webodf.js| 355267 | 349908

Fixes #785
well, the idea was to only go to the end of the line with that reg exp, so catching more, even if not a problem per se, would have been not exactly matching the comment, making future code readers think something could be wrong.
anyway, now picked the regexps you proposed. Creates the very same result with the current webodf.css as the other, so taken as first proof of minimal risk :)