.css(), the values ​like "+=50%" are now managed (like .animate())
Tests: remove all the empty line whitespace
Core: Fix trim in Android<4.1
Css: Don't check fill-opacity in Android 2.3, it's not supported
Event: Blacklist the onbeforeunload test in Android 2.3

Similarly to iOS, Android 2.3 has the onbeforeunload property on window
but doesn't support the event. This commit blacklists the test there as well.
Effects: Don't check fill-opacity in Android 2.3, it's not supported
Support: Skip style-based tests when element.style is undefined

Fixes #14785
Ref #13754
Ref badcd1b6f301e6253405f17759c1270549a34e12
Support: Reduce size

Ref a7ea12a9a7c696a14455bfe4bfebf984dd329832
Bower: add main property, move Sizzle to devDependencies, add license property

Fixes #14798
Close gh-1516
Ref gh-1338
Bower: stop ignoring yourself, bower

Ref #14798
Ref gh-1516
Ref gh-1338
Core: Remove native String#trim usage to save size

Fixes #14794
Core: Arrays like [42] should fail .isNumeric()

Fixes #14179
Ajax: .load() should trim its selector

Fixes #14773
Event: Allow triggerHandler(beforeunload)

Fixes #14791
CSS: Return values should be numbers

Fixes #14792
Core: Do not run window.onready when ready

Fixes #14802
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