Improve the include / exclude SQL generation in `get_terms()` by using `IN` and `NOT IN` where applicable. Adds unit tests for include / exclude.

Props sirzooro, duck_.

Fixes #11823.


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git-svn-id: http://core.svn.wordpress.org/trunk@25141 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Pass the taxonomy around to relevant nav menu actions to avoid arbitrarily deleting all items with `menu-item-type` of `taxonomy`. Adds unit test for `wp_get_associated_nav_menu_items()`.

Props garyc40, SergeyBiryukov.
Fixes #15264.


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git-svn-id: http://core.svn.wordpress.org/trunk@25142 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Search term `name` and `slug` when the `search` arg is passed to `get_terms()`. Adds unit test.

Props wojtek.szkutnik.
Fixes #13992.


Built from https://develop.svn.wordpress.org/trunk@25164


git-svn-id: http://core.svn.wordpress.org/trunk@25143 1a063a9b-81f0-0310-95a4-ce76da25c4cd