Issue #1149866 by jessebeach, effulgentsia, ethanw, corbacho, et al: Added Backbone.js and Underscore.js to core.

Issue #1277352 by quartsize, lewisnyman, nod_, JohnAlbin, kika, dcmouyard: Fixed Responsive vertical tabs.

Issue #1263302 by andypost, peterpoe: Fixed States API disabled state handler filters out nonexistent class 'form-element'.

Issue #1608878 follow-up by tim.plunkett: Move Dropbutton CSS to dropbutton.base.css from node.admin.css.

Issue #1439462 by nod_, Jelle_S: Drop our custom $.support.positionFixed and use jQuery's $.support.fixedPosition.

Issue #1608878 by jessebeach, tim.plunkett, dead_arm, nod_, sun, effulgentsia, Everett Zufelt, geerlingguy: Added CTools dropbutton to core.

Issue #1276908 by jessebeach, nod_, moshe weitzman, lewisnyman, webchick: Fixed Administrative tables are too wide for smaller screens.

Issue #1575060 by andypost, mcjim, nod_: Fixed ajax_html_ids() are broken for forms with file element (encoding=multipart/form-data).

Issue #846182 by reglogge, szantog, geerlingguy: Fixed Seven theme form buttons have no hover state.

Issue #1700210 by nod_, aaronbauman: Fixed After editing a field machine name, then re-ordering the field, machine name field disappears.

Issue #1749782 by pascalduez: Use event.preventDefault(); and event.stopPropagation(); instead of return false;.

Issue #1071818 by JeremyFrench, nod_, reglogge, anthbel, xjm, sun, NROTC_Webmaster, lliss, Cottser: Fixed Lazy-loading CSS fails in IE.

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

Issue #1085590 by Rob Loach, keichee, tim.plunkett, mfer, ericduran: Update jQuery UI to the latest in the git repository.

- Patch #1016056 by nod_: added Hide tabledrag handle and 'Show row weights' when there is only one item in list.