XML-RPC: Send 405 Method Not Allowed for GET requests.

props maxcutler.
fixes #20986.

Built from https://develop.svn.wordpress.org/trunk@31004


git-svn-id: http://core.svn.wordpress.org/trunk@30985 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Use proper hash notation for `wp_dropdown_categories()` docblock.

See #30306.
Built from https://develop.svn.wordpress.org/trunk@31005


git-svn-id: http://core.svn.wordpress.org/trunk@30986 1a063a9b-81f0-0310-95a4-ce76da25c4cd
In `wp_dropdown_categories()`, allow the term field used to populate option valuesto be specified.

The new 'value_field' parameter makes it possible to set term slugs (or some
other term property) as the 'value' attribute of the option elements generated
by `wp_dropdown_categories()`. This additional flexibility reduces the effort
required to translate term_id to other term fields when processing form
submissions that include values from taxonomy dropdowns. See #30865 for a
use case.

Props collinsinternet.
Fixes #30306.
Built from https://develop.svn.wordpress.org/trunk@31006


git-svn-id: http://core.svn.wordpress.org/trunk@30987 1a063a9b-81f0-0310-95a4-ce76da25c4cd