Improve handling of wide tables and forms in 3 column drupal themes by allowing user to hide right sidebar and display CiviCRM page element overflows

A clickable icon at the table / form level which the user can click to show the overflow (and hide the right sidebar to remove visual clutter).

(Dan Kurtz is working on a patch for this. If we get it in time, this issue can be moved up to 2.2.)

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Some prototype code for doing this via dojo:
<a href="#" id="open-container" onClick="dojo.query('#crm-container').style('overflow', 'visible'); dojo.query('#sidebar-right').style('visibility', 'hidden'); dojo.query('#close-container').style('visibility', 'visible'); dojo.query('#open-container').style('visibility', 'hidden'); return false;" >»</a>
<a href="#" id="close-container" onClick="dojo.query('#crm-container').style('overflow', 'auto'); dojo.query('#sidebar-right').style('visibility', 'visible'); dojo.query('#close-container').style('visibility', 'hidden'); dojo.query('#open-container').style('visibility', 'visible'); return false;" >»</a>