#256092 by Pancho et. all. Added missing $Id$ tags to several documents, and fixed the tags on a couple css files which had the wrong comment markers on the tags. Also wrote small updates to the text files directing people to more information online.

A rounded corners style; moved the style settings to pair with the layout settings; now all panel types can have styles.

Pulled panels page settings out and created a panels_common.inc so that panels_* can use some common features if they need them.

New javascript drag & drop; menu_rebuild on panel page save; fix add content button positionin garland