(cherry picked from commit 87730673)

(cherry picked from commit 31a19a80)

(cherry picked from commit 74490f86)

Closes gh-1018
(cherry picked from commit c45f6095)

Conflicts:

	src/effects.js

Closes gh-1022
Closes gh-1021
(cherry picked from commit 781a5c0b)

Remove the Makefile and replace the submodule update with a grunt task. Thanks to @ryanneufeld. Closes gh-953.

Thanks @curiousdannii!

* Clean up testinit and testrunner

* Uncomment isLocal (at least make sure it is declared)

* Rephrase environment assertions to make sense if one reads
  them when they pass.

* Optimise an expensive loop that might be the cause of this
  in IE6: http://cl.ly/image/3f20053m112n

Do not iterate over functions. Fixes #12665. Unit tests added. Thanks to @kselden for finding the bug.

Revert "Chrome fails in ajax.js tests because TestSwarm/Ngnix won't give HEAD requests any respect. Skip them rather than hear Swarmy call FAILURE on each run."

This reverts commit 9c5089a6.

These were not the droids we were looking for. Actually caused by a BrowserStack issue.

This is only a unit test fix because the bug was tangentially fixed by a different commit

Sizzle: account for external document contexts (such as iframes) in combinator checks. Fixes #12572.