Issue #1387634: Allow features to be able to see the default panelizer panel after it has been modified by the user.

This is so that we can use default selection when we build our node
forms through the page manager with variants.

Issue #1361648 by OnkelTem: Ensure comment module exists before adding comment panes to the default node panelizer panel.

Issue #1361620: Saving a panelized panel that was using a default panel could modify the default panel display.

Issue #1360948: Has no default, no choice should not show tabs for default panel configuration in admin pages.

Issue #1343480: custom CSS on a panelizer page should be added as part of the theme layer to have highest priority.

Issue #1329280: Add an "object default" to the css so that ctools export gives it a default properly.

Add panelizer paths to admin paths and fix panelizer task handler to work properly for default panelizer panels.

Panelizer 2.x rewritten to have a more entity focused architecture. It also fully supports revisioning and from multiple prebuilt panels per node.

Issue #1298150 by DamienMcKenna: Separate variables so that panelizer can be more easily integrated with features.

Issue #1283246 by John Morahan: Panelizer context not fully updated to D7 where "cache" plugin was necessary.