In `wp_update_term()`, limit duplicate slug checks to the same taxonomy as the updated term.

In 4.1 [30240], `wp_insert_term()` was modified to allow the creation of terms
with duplicate slugs, as long as the terms are in different taxonomies.
`wp_update_term()` didn't get the corresponding modification, with the result
that term updates fail when the term being updated shares a slug with an older
term, regardless of that older term's taxonomy.

Props ipm-frommen.
Fixes #30780 for trunk.

git-svn-id: https://develop.svn.wordpress.org/trunk@30985 602fd350-edb4-49c9-b593-d223f7449a82
TinyMCE wpView: when clicking on the Edit button, move the focus back to the editor before opening the modal. This is needed for IE so TinyMCE can save the proper DOM "bookmark", and makes it possible to move the focus to the modal after it is opened.
See #30817.

git-svn-id: https://develop.svn.wordpress.org/trunk@30986 602fd350-edb4-49c9-b593-d223f7449a82
Switch to container-based infrastructure on Travis CI.

The container-based infrastructure has more memory and more cores.  It also is designed to startup faster. We give up the ability to use sudo, but we aren't using that right now so we should be good.

Props netweb, tw2113.
Fixes #30822.



git-svn-id: https://develop.svn.wordpress.org/trunk@30987 602fd350-edb4-49c9-b593-d223f7449a82
Update npm on Travis CI as a part of build

Travis has an outdated version of NPM.  While this is currently only generating a warning, in the future it could cause actual errors.

Fixes #30823



git-svn-id: https://develop.svn.wordpress.org/trunk@30988 602fd350-edb4-49c9-b593-d223f7449a82
Add jQuery UI Core as a dependency for qUnit tests

[30919] added more qUnit tests for the Customizer. One of the dependencies for these tests is qUnit. Otherwise we end up with an error due to an unsupported pseudo.

https://travis-ci.org/aaronjorbin/develop.wordpress/jobs/44873635#L425 shows an example of the failing test.

Props ocean90.
see #30701.
Fixes #30754.



git-svn-id: https://develop.svn.wordpress.org/trunk@30989 602fd350-edb4-49c9-b593-d223f7449a82
In Imagick tests, instantiate `WP_Image_Editor_Imagick` directly instead of calling `wp_get_image_editor()`.

This is for greater consistency with other image editor tests.

Props voldemortensen.
Fixes #30820.

git-svn-id: https://develop.svn.wordpress.org/trunk@30990 602fd350-edb4-49c9-b593-d223f7449a82
Customizer: Improve IE 8 compatibility.

* Use square bracket notation for `default` keywords.
* Use Underscores `indexOf` for arrays.

props westonruter, ocean90.
fixes #30781 for trunk.

git-svn-id: https://develop.svn.wordpress.org/trunk@30991 602fd350-edb4-49c9-b593-d223f7449a82
Customizer: Use correct event variable when moving widgets to another widget area. 

Fixes "ReferenceError: event is not defined error." in Firefox.

props tywayne.
fixes #30818.

git-svn-id: https://develop.svn.wordpress.org/trunk@30992 602fd350-edb4-49c9-b593-d223f7449a82
Pass `$resource_type` to 'get_ancestors' filter.

The `$resource_type` argument was added to the `get_ancestors()` function in
[30141]. In that changeset, the documentation for the filter was updated to
indicate that it would receive `$resource_type` as a param, but the filter
itself was not updated accordingly.

Props tmatsuur, DrewAPicture.
Fixes #30843.

git-svn-id: https://develop.svn.wordpress.org/trunk@30993 602fd350-edb4-49c9-b593-d223f7449a82
Correct $taxonomies parameter description in get_terms() filters.

props dlh.
fixes #30851.

git-svn-id: https://develop.svn.wordpress.org/trunk@30994 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fifteen: add styles for multisite registration forms.

Props valendesigns, fixes #30776.

git-svn-id: https://develop.svn.wordpress.org/trunk@30995 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fifteen: pinking shears.


git-svn-id: https://develop.svn.wordpress.org/trunk@30996 602fd350-edb4-49c9-b593-d223f7449a82
Twenty Fifteen: fix missing style for menu in small screens.

Props valendesigns, fixes #30857.

git-svn-id: https://develop.svn.wordpress.org/trunk@30997 602fd350-edb4-49c9-b593-d223f7449a82
Apply 'taxonomy_parent_dropdown_args' filter when editing terms.

Added in WP 3.7 [25123], the 'taxonomy_parent_dropdown_args' filter affected
only the term creation interface. This changeset introduces parity by ensuring
that it is applied when editing terms as well.

The new `$context` parameter indicates whether the filter is being applied in
a 'new' or 'edit' context.

Props TimothyBlynJacobs, DrewAPicture.
Fixes #29853.

git-svn-id: https://develop.svn.wordpress.org/trunk@30998 602fd350-edb4-49c9-b593-d223f7449a82
Fix incorrect `@since` tag introduced in [30998].

Props dimadin.
See #25853.

git-svn-id: https://develop.svn.wordpress.org/trunk@30999 602fd350-edb4-49c9-b593-d223f7449a82