Issue #1913086 by jessebeach, Wim Leers, mgifford, nod_: Generalize the overlay tabbing management into a utility library.

Issue #1847084 by jessebeach, trawekp, LewisNyman, nod_, tarekdj: Fixed Vertical toolbar doesn't work with overlay (measure/track displacing elements better + provide change events for them).

Issue #1137920 by jessebeach, lewisnyman, tkoleary, Bojhan, webchick, benjifisher, nod_, sjbassett, kathryn531, effulgentsia, Everett Zufelt: fixed toolbar on small screen sizes and redesign toolbar for desktop.

- Patch #1260800 by David_Rothstein, lewisnyman, yoroy, nod_, thedavidmeister, effulgentsia: kill the overlay for widths below 640 pixels.

- Patch #1651270 by effulgentsia: remove IE8-specific workaround for lack of CSS3 box-shadow support.

- Patch #1183208 by effulgentsia, Niklas Fiekas, katbailey, no_commit_credit, catch: remove variable_get()('clean_url()') and switch to index.php/path pattern for dirty URL support.

Issue #1431076 by c960657, nod_, purencool, Nor4a: Fixed Overlay does not work with prefixed URL paths .

Issue #1006042 by ksenzee, grendzy: Fixed Links outside the overlay with existing fragments are broken.

Nate Lampton authored Oct 30, 2011 and catch committed Nov 01, 2011

Issue #22336 by quicksketch, scor, boombatower, and rfay. Move all core Drupal files under a core subdirectory.

- Patch #1174686 by ksenzee: overlay parent improperly opens child overlay on specific external links.

- Patch #759844 by jpmckinney, dixon_, plach, ksenzee, fabsor, pillarsdotnet: overlay does not work with prefixed URL paths.

- Patch #896364 by frega, effulgentsia, Jacine, sun, David_Rothstein, Jeff Burnz, james.elliott, casey, mgifford: screen reader users and some keyboard only users need a clear, quick way to disable the overlay.

- Patch #841184 by ksenzee, aaronbauman, aspilicious: 'Skip to main content' link doesn't work correctly in the overlay.

- Patch #716612 by Everett Zufelt, casey: another step twoards making the overlay (more) accessible to screen reader users.

- Patch #667012 by ksenzee, casey, David_Rothstein: remove the opening of external links in a new browser window.

#655416 by casey, yoroy, BTMash, Bojhan, Gábor Hojtsy, sun, ksenzee, oseldman, jrguitar21, et al: 'Demonstrate block preview' should not open in the overlay, and should reflect the regions in the front-end theme.

- Patch #663126 by casey, ksenzee, seutje: active items in top level IA don't have the light gray background when overlay is enabled.

- Patch #667012 by ksenzee, casey: remove (or fix) the opening of external links in a new browser window.