[JUX2] [14] Proposal for an improved Quick-Icons panel

This proposal simplifies menus/quick-icons and groups them at the control panel. It implements this this way:

![quick-icons](https://f.cloud.github.com/assets/47402/1184400/2cbf8180-2247-11e3-96b2-344a014eac2a.png)

To be compared with previous 3.1 panel:

![cpanel-old-isis](https://f.cloud.github.com/assets/47402/1065016/43e745ec-1369-11e3-8ed2-27a8da5cacd0.png)

It also fixes:
- Hathor issue for updates warning in quick-icon
- RTL issue foudn in NAV and HEAD during tests

And issue of previous PR that displayed titles of empty groups of quick-icons.

Previous PR: https://github.com/joomla-projects/joomla-cms/pull/163

Related FR: http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=31871