Core: Work around loss of precision from parseFloat

Fixes #15100
Tests: Clean up isNumeric tests
CSS: Do not throw on frame elements in FF

IE9-10 throws on elements created in popups (see #14150), FF meanwhile throws
on frame elements through "defaultView.getComputedStyle" (see #15098)

Use "defaultView" if in the popup which would fix IE issue,
use "window.getComputedStyle" which would fix FF issue.

And everybody wins, except performance, but who cares right?

Fixes #15098
Ref e488d985cfb10ab8c684bbc6a9b8ff3eae23bf83
Ajax: Always use script injection in globalEval

Fixes #14757
Ref bbdfbb4ee859fe9319b348d88120ddc2c9efbd63
Effects: Remove needless operations in tests

Ref 10024c25820f08139f11d924cec552a26dfbba18
Effects: Reintroduce use of requestAnimationFrame

Same as before, just use don't use prefixes, since they pretty match useless now
and use page visibility API to determine if animation should start.

Also null the requestAnimationFrame attribute in window for tests since
sinon does not provide fake method for it.

Fixes #15147
Ref 72119e0023dcc0d9807caf6d988598b74abdc937
Effects: Improve raf logic

* Make animation behave as if jQuery.fx.off = true if document is hidden

* Use cancelAnimationFrame in jQuery.fx.stop

Ref 708764f47b0c8de152bbb444d0f608db558b76ed
Build: Move test to appropriate module

Ref fbdbb6fd431a3f598b581079b0ca37c399d369d4
Build: Update commitplease dev dependency

Ref 39b76064d9400295a383291ab6e821e259b67832
Build: ignore test dependencies for npm install
Build: Upgrade to grunt-bowercopy 1.0.0
Build: Remove unused Sizzle test files
Build: Move all external libraries to external directory

Closes gh-1593

Conflicts:
	Gruntfile.js
	test/index.html
Build: update Sizzle to 1.11.1 and include license
Build: update grunt-bowercopy
Selector: Remove "#" exception for identifier tokens

Port Sizzle test change from:
https://github.com/jquery/sizzle/commit/f204a6112216f31685717d9fc1bf6cabf42b2ef1

(cherry-picked from 86e62d8b37ff9ad40e7c21c2c0c440a9cdfc550e)
Build: Add "timers_ie.js" file back to the repo
Build: Correct indentation issue
Core: Consistently use local reference to access()

Ref 2fb719e5aa885232c5347576e9f9e1e341a7ba15
Ref 2063d6c1896b0c46c39fa0fdecef817f2e6f57c3
Readme: Fix punctuation in tile

Ref df62159296e9de8b04653ba999a32f9be7bb2a73