This is a major revamp of the approach we use for IE change events. Instead of trying to track and simulate, we lazy-attach real change events to inputs and have only one workaround for check/radio. Somewhat more resource intensive but closes several sticky bugs. The onchange is still triggered for check/radio on blur but no double-trigger on any element occurs.

Landing pull request 509. Add a comment explaining the use of document.getElementsByTagName('body')[0] instead of document.body.

More Details:
 - https://github.com/jquery/jquery/pull/509

Landing pull request 491. Fix #7322. Make `.is()` with a positional selector work like delegated event logic. Fixes #7322.

More Details:
 - https://github.com/jquery/jquery/pull/491
 - http://bugs.jquery.com/ticket/7322

Landing pull request 512. 1.7 - removeData now takes space separated lists and arrays of keys - Fixes #7323.

More Details:
 - https://github.com/jquery/jquery/pull/512
 - http://bugs.jquery.com/ticket/7323

Landing pull request 492. 1.7 Remove multiple attributes (Symmetry with removeClass) Combines patches submitted by leeoniya, zertosh and my own tests. Fixes #5479.

More Details:
 - https://github.com/jquery/jquery/pull/492
 - http://bugs.jquery.com/ticket/5479

More Details:
 - https://github.com/jquery/jquery/pull/477
 - http://bugs.jquery.com/ticket/6809

More Details:
 - https://github.com/jquery/jquery/pull/490
 - http://bugs.jquery.com/ticket/6485

More Details:
 - https://github.com/jquery/jquery/pull/331
 - http://bugs.jquery.com/ticket/7102

Landing pull request 503. 1.7 data: set a flag in the private data cache to avoid having to scan attributes multiple times - Fixes #8909.

More Details:
 - https://github.com/jquery/jquery/pull/503
 - http://bugs.jquery.com/ticket/8909

More Details:
 - https://github.com/jquery/jquery/pull/500
 - http://bugs.jquery.com/ticket/8921

More Details:
 - https://github.com/jquery/jquery/pull/496
 - http://bugs.jquery.com/ticket/9280

More Details:
 - https://github.com/jquery/jquery/pull/510
 - http://bugs.jquery.com/ticket/9699

Revert "Fix #6593. Don't trigger `change` event twice when simulating it on IE." Add inline handler monitor to delegatetest.html so we can see it fail.

This reverts commit e77686495b6e34938575c9c0fe978cb4a0be6f05.

This reverts commit 3d0de29d5615c1b1d74c72e6272484961a4ba243.

Fix #9593. Create a new jQuery.Event rather than a plain object when simulate()ing events. Fix a related issue with not passing src to jQuery.Event constructor.

Remove the relatedTarget adjustment for mouseenter/leave events, it's an ambiguous case anyway and it is expensive to do.

And use the /dist version of jquery.js, willya?

Rework #1486 patch to avoid `try/catch` and look for hidden elements by `.offsetWidth`. Unit test currently disabled due to Chrome bug.

Fixes for IE8. Avoid killer recursion in special events during removal. Use q instead of quote in unit tests.