Merge pull request #1574 from sylus/7.x-2.x

Updates for 2.x branch.
Merge pull request #1576 from sylus/7.x-2.x

Updates for 2.x branch.
Merge pull request #1579 from sylus/7.x-2.x

Updates for 2.x branch.
Merge pull request #1581 from sylus/7.x-2.x

Updates for 2.x branch.
Update WetKit Core for Panopoly Magic Single Preview.
Update WetKit Theme for Additional Modal styles for single preview.
Update WetKit Widgets for Issue #2129273 by sylus: Media alt attributes only work via the interface (Field.attach.inc)