Fix IE10 bug when cloning an object element without a parentNode
Manual merge after fetch upstream
Fix weird clone bug and add a unit test to verify
Updated the comment above the fix
Add support check, added assertion to check if cleared, add edge case for backgroundPosition
Remove test file that I didn't mean to get into the previous commit
Fix #10943, tabindex not set properly on clone in IE7. Close gh-937.

This is only a unit test fix because the bug was tangentially fixed by a different commit
Fix #12357: be more kind to non-browser environments. Close gh-938.
Fix #12537, element.css('filter') returns undefined in IE9. Close gh-942.
Since .getAttribute() returns strings, we should check for them.
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 9c5089a60d479a959b290a5b4ab8ef38c985e963.

These were not the droids we were looking for. Actually caused by a BrowserStack issue.
Fix #12637: restore 1.8.1 ajax crossDomain logic. Close gh-944.
Fix #12583: Don't ignore disabled property of select-one, close gh-932.
Sizzle: throw an invalid selector exception for trailing-comma selectors. Fixes #12643.
body default display is always block. @mikesherov was right and this is the proof. Fixes #10227
Update AUTHORS.txt based on CLA responses.
fix failure from bad markup leaving an element behind. Closes gh-946
Do not iterate over functions. Fixes #12665. Unit tests added. Thanks to @kselden for finding the bug.
Test: Clean up and fix misc issues

* 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
Break big-html check into its own test for IE6.