Update to the latest jQuery version.
Review Request #1122 — Created March 12, 2018 and updated
This change moves us over to the latest versions of jQuery and jquery.form. This was relatively painless, with only a few changes being necessary: - `$(func)` or `$(document).ready(func)` now always invoke their callbacks asynchronously, even when the DOM is already loaded. This interfered with one of the PageManager unit tests. - Our autocomplete fork had some manual checks for old Opera browsers which are obsolete, and didn't work now that `$.browser` is gone. - `$.fn.load` used to do two things (one loaded stuff, the other attached to the load event) and now only does one. We had one place that was using the removed behavior (the event), which has been changed to `$.fn.on`. - The naming scheme for the widget in element data changed in jQuery UI, so that the old data name "rbautocomplete" is now "uiRbautocomplete". - `$.fn.andSelf` has been removed, in favor of `$.fn.addBack` (which always existed, and did exactly the same thing). Testing done: - Audited the codebase for anything that would have been problematic with deprecations and removals. - Ran js-tests. - Smoke tested the UI. Reviewed at https://reviews.reviewboard.org/r/9714/