Introduce the Panels stylizer module which builds on the CTools stylizer base to create user definable, recolorable styles.

#612704 by c960657: panels_get_pane_content() inappropriately created a blank context when no contexts were available.

#624710: fix an old, old bug where the default empty context was not being appropriately wrapped in an array.

#607420: Visibility rules did not appear in the list when added to a pane (though they still applied).

Add a new field to allow setting a panel title from one of its panes.

Remove some outdated, unnecessary files and add jQuery version protection so that multiple copies of jquery or other things do not mess us up.

Change use of "content" div to "pane-content" and "title" to "pane-title" to prevent conflicts with other things that use these fairly generic classes.

Clean up caching of displays in page manager. Still need to do mini panels and panel nodes, I suppose.

Added allowed layouts to settings form for panel pages, nodes, minis.

Fix panel page type to actually respect the contexts.