Add cache invalidation when updating a term, example: create a category, assign it to a post, edit the category. Currently, the post's term cache is not updated. When updating terms in a given taxonomy, invalidate the object term caches linked to that taxonomy. 

Introduce `get_taxonomy_last_changed()`, `set_taxonomy_last_changed()`, and `post_taxonomy_is_fresh()`.

`post_taxonomy_is_fresh()` is only called in `get_object_term_cache()` - at which point the taxonomy's `last_changed` value is checked against the post's `{$taxonomy}_last_changed` value.

`set_taxonomy_last_changed()` is called whenever directory database queries are made that insert new terms or affect existing terms.

Fixes #22526.


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git-svn-id: http://core.svn.wordpress.org/trunk@26970 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Regenerate the term hierarchy cache (`{taxonomy}_children`) when it is out of sync with the passed taxonomy's `last_changed` value.

Introduces `taxonomy_hierarchy_is_fresh()`, which is only called in `_get_term_hierarchy()`. The taxonomy's `last_changed` value is checked against the value of `wp_cache_get( 'hierarchy_last_changed', $taxonomy )`.

Adds a unit test - `Tests_Term:test_hierachy_invalidation()`.

See [27101], which makes this type of cache invalidation possible.
Fixes #14485.


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JSHint fixes for media-views and Gruntfile.

props gcorne.
fixes #27032, #27033.

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Merge colors.css into wp-admin.css. Non-default color schemes became overloads rather than swaps in the 3.8 redesign. Benefits include:

* No more border-width, border-style, border-color insanity.
* Point releases are much less likely to require extra finagling to avoid rebuilding the color schemes.
* Yours truly has a better overall vision of ~14,000 lines of admin CSS and where we go from here.

1,065 net lines of red, y'all.
props helen, jorbin. fixes #18380.

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Some tweaks to [27106]:

* Add more @todo markings and remove one that's been resolved.
* Restore a missing comma in a `.wp-badge` background rule, and add a comment reminding us why it's there.

see #18380.

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In `get_terms()`, don't set automatically `hierarchical` to `false` when `parent => 0` is passed. The default value for `parent` is `''`.

In `_get_term_children()`, don't skip a top-level term without first including its children in the returned term list. Ironically, the call to `_get_term_children()` in `get_terms()` has a comment stating `"Make sure we show empty categories that have children."`, but it didn't work if you were retrieving top-level categories only.

All unit tests pass. Added a unit test based on the use case described in this ticket.

Fixes #26903.


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Fix some hover/focus styling and specificity issues. see #18380.

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git-svn-id: http://core.svn.wordpress.org/trunk@26976 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix scrolling inside the Visual editor on MacOS, add the same functionality to the Text editor, see #27013
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git-svn-id: http://core.svn.wordpress.org/trunk@26977 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Fix the conditional enqueueing/printing of colors stylesheets, without breaking dependencies.

fixes #18380.
see #20729 which should properly fix this.

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Network install: When showing the path to wp-config.php make sure our slashes are normalized.

props VarunAgw.
fixes #27025.

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Add imgur to the list of oEmbed providers.

props bradparbs.
fixes #21632.

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git-svn-id: http://core.svn.wordpress.org/trunk@26980 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Revisions browser: The back button should return to the post you were editing (use replaceState instead of pushState).

props adamsilverstein.
fixes #26997.

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git-svn-id: http://core.svn.wordpress.org/trunk@26981 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Use a float for last_changed microtime cache values.

microtime() by default returns a string with a space, which isn't allowed for keys in some cache backends.

props _jameslee, drozdz.
fixes #27000. see #23448.

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Fix typo in wp_set_auth_cookie() description.

props drozdz.
fixes #27046.
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Twenty Fourteen: fix gap above static pages, props SergeyBiryukov. Fixes #26694.
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Twenty Fourteen: make sure `featured` tag is hidden on front-end views as expected. Add a check for the tag name in case we're using default values and the default ID of `0` does not match the term id of the `featured` tag.

Props obenland, fixes #26732.
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Use .screen-reader-text class instead of an alt attribute for overlay button labels on Themes screen.

props bramd.
fixes #26603 for trunk.
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Twenty Fourteen: delete the `featured_content_ids` transient on theme switch to make sure child themes can override the Featured Content quantity value. Also remove quantity parameter so child themes can change the amount of featured posts with `$max_posts`.

Props obenland, see #26660.
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Twenty Fourteen: fix unreachable links when the content area is shorter than the sidebar in smaller viewpoints. Props celloexpressions, see #26782.
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Twenty Fourteen: translate `featured` tag slug used to link to specific tags in Posts editor. See #26526.
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