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
By just going for comments on full lines or at line end I hoped to do less risky matches. Because with mid-line comments I was not sure if "/*" or "*/" could be used for real CSS purposes, resulting in bad matches. If you are sure that the chance of such character pairs with real CSS content is rather low, your variant might be simpler indeed (but then there are no mid-line coments in current webodf.css ;) ).