2012-03-02 - Stylesheet normalization

After this, the stylesheets follow these conventions:

* Every directory in css/ is considered a style to be chosen.
* lx-office-erp is used as the fallback style if no style was found or the
  style chosen was invalid.
* Missing stylesheets for the other styles have been
  linked from lx-office-erp, so that they will used like before.
* If you edit a file, make sure it's not a symlink.
* The previous named stylesheets are now main.css in their respective directories.
* menuv3 and menuv4 are now distict so that it's possible to include both
  without overriding each other.
* All relative image links needed to get bumped an additional ../
* If you add another style, be sure to test tabs, calendars, all menus,
  autocompletion, charts, and multiselect.