Issue #1359500 by Devin Carlson, theborg: Fixed Minor html bug in Seven's page.tpl.php (double occurrence of "ul" on secondary local tasks).

Issue #1015798 by oriol_e9g, Mohammed J. Razem, dimitriseng, xjm, mstrelan, drunken monkey: Fixed Fieldsets inside vertical tabs have no title and can't be collapsed.

Issue #1384224 by philbar, Plazik, oriol_e9g: Fixed Resize Site Logo in Seven Theme Maintenance Pages.

Issue #1376502 by TR, vitalsouto: Fixed Code cleanup: Removed empty PHP blocks from templates left over from git migration.

Issue #908282 by jbrown, pillarsdotnet: add width and height attributes to increase front-end performance.

#746470 by follow-up by aspilicious, Jacine, jbrown, sgabe, et al: Add border-radius for IE9 / Opera 10.50

#544398 by Gábor Hojtsy, mr.baileys: Fixed Delete buttons look disabled in Seven theme even though they're not

#599706 follow-up by JohnAlbin, sun: Regression: Restore consistency to theme_menu_local_tasks() theme function

- Patch #896828 by Jeff Burnz, Manuel Garcia, yoroy, bleen18: no visual connection between the active tab and its content.

- 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 #639460 by Jeff Burnz, effulgentsia, Jacine, mgifford, james.elliott: evaluate CSS of #skip-link, .element-focusable, and upcoming 'disable overlay' links for their impact on contrib/custom themes.

#931682 follow-up by aspilicious, corbacho: Be more specific about which headings should not be bold in Seven.

- Patch #769226 by Owen Barton, sun, effulgentsia, alanburke, bleen18, mfer: optimize JS/CSS aggregation for front-end performance and DX.

#699858 by David_Rothstein, catch, yoroy, sun, ronald_istos, et al: Fix admin/by-task is confusing because it looks too similar to admin/config. Makes admin/by-task a very minimal view, and makes admin/by-module a more fully fledged index.