Build: Fix AMD option for custom builds

Fixes #14859
Manipulation: don't use Object.keys for consistency

Fixes #14659
Ajax, Effects: Disable Chrome 31 workarounds
Css: Revert 24e587929f62428e1959b10aace6dc4fd65ab397

The workaround to be able to change !important styles broke the browser
keeping the old CSS value if the new one was rejected. Patching it would
involve a significant perf hit (~33%) so the initial patch needs to be
reverted instead.

Tests by m_gol & gibson042.

Fixes #14836
Closes gh-1532
Css: Fix tests

It's not easy to find a CSS property that is implemented even in
ancient browsers and that returns a consistent result among browsers
when passed through .css(). color didn't work since Firefox normalizes
it an empty value to rgb(0, 0, 0).
Build: Make it possible to change browserSets in the testswarm task
Build: Allow to specify timeout in the testswarm task
Build: Fix testswarm task, use API correctly
Support: Make the support matrix for iOS 6 match iOS 7 as well
Event: Call underlying stopImmediatePropagation when present

Fixes #13997
Core: Bump timeouts to stabilize doc ready test

The "document ready when jQuery loaded asynchronously" test fails all the time
in iOS7 and sometimes in other browsers. Bumping the timeouts *might* help
these other browsers to be less flakey here.
AMD: Note on AMD best practices

Fixes #14687
Closes gh-1478
Readme: updating QUnit information

updates QUnit reference site and method naming.

Closes gh-1493
CSS: Add flex-grow and flex-shrink to cssNumber

Fixes #14888
Closes gh-1536
Build: Refactor testswarm Grunt task options

Add a possibility to specify the project name. Infer browserSets & timeout
out of it instead of defining it in the Jenkins configuration.
Readme: Fix subsection titles and grammar, thanks @robgraeber

Fixes gh-1540
Event: Treat Pointer events like mouse events, #14741

Ref #14741
Ref gh-1503
Event: Unit test for #14741 fix

Fixes #14741
Closes gh-1503
Core: Blacklist the ready test on async-loaded jQuery in iOS7

Fixes #14882
Build: Change the timeout for the weekly job from 4h to 1h