Add support for password protected posts

Password protected posts are now fully supported, you can create edit and read password protected posts in the REST API. There is now a protected attribute in the content and excerpt fields in post response.

To view password protected posts via the API, use the password query parameter to provide the post's password.

(props @joehoyle, #2720)

Allow returning an error from field update callbacks

Fields added via register_rest_field can now return an instance of WP_Error in the update_callback.

(props @rmccue, #2702)

Update the wp-api.js client from the client-js repo.

(props @joehoyle, #2746)

Add relevance orderby to posts endpoint

(props @websupporter, #2579)

Ability to order by slug, email and url on the users endpoints.

(props @joehoyle, #2721)

Add sticky parameter to the posts endpoint.

(props @joehoyle, #2708)

Add link to comment children, allowing threaded comment querying

(props @BE-Webdesign, #2662, #1612)

Avoid unnecessary SQL query by passing $user_nicename

(props @danielbachhuber, #2435)

Don't allow reading / creating of posts with no parent

(props @rachelbaker, #2744)

Mark Users' capabilities property as readonly

(props @danielbachhuber, #2440)

Mark some post properties as readonly

(props @danielbachhuber, #2438, #2439)

Use WPINC instead of wp-includes/

(props @websupporter, #2461)

Return error, if user can't list users & content=edit

(props @websupporter, #2463)

Conditionally model the term response based on its schema

(props @danielbachhuber, #2470)

Include Post data on the response object when declared

(props @websupporter, #2423, #2416)

Add boolean type support to rest_validate_request_arg()

(props @westonruter, #2478)

Fix create/update requests not processing data included in the schema

(props @websupporter, #2479)

Remove Unused Parameter in lib/endpoints/class-wp-rest-controller.php

(props @hideokamoto, #2500)

Update post schema status description to reflect csv support.

(props @coderkevin, #2534)

Allow Comments to be created with a passed author_ip

(props @rachelbaker, #1880)

The get_the_excerpt filter expects the post object as of WP 4.5.

(props @lgedeon, #2553)

Introduce WP_REST_Controller::get_post() for allowing plugins to mutate
get_post()'s return value

(props @westonruter, #2535)

Use show_in_rest to determine "public" post types to check

(props @danielbachhuber, #2384)

#2426 Fix inconsistent type for user caps

(props @BE-Webdesign, #2429, #2426)

Define user type as a string, not an array

(props @danielbachhuber, #2556)

Fix failing test: Typecast the user_id in search to a string

(props @rachelbaker, #2617)

#2587 Fix registered date schema

(props @BE-Webdesign, #2628, #2587)

Fix forum url and installer-name in readme

(props @torounit, #2656)

Document options of the "status" parameter for Post collection GETs

(props @kadamwhite, #2645)

Improve WP_REST_Controller::filter_response_by_context().

(props @tfrommen, #2641)

#2424 Consistent slashes in rest_url() usage

(props @BE-Webdesign, #2428, #2424)

Add filters to allow for relevance search

(props @websupporter, #2665)

Alter default comment sort order to be "desc"

(props @kadamwhite, #2684)

Add raw and rendered to revisions schema

(props @websupporter, #2693)

"WP API" -> "WordPress REST API" in README files

(props @kadamwhite, #2697)

Improve boolean validation from schema

(props @BE-Webdesign, #2704, #2616)

Fix typo (PUT vs POST) in readme.md

(props @kadamwhite, #2716)

Add Codecov configuration

(props @danielbachhuber, #2718)

Fix inefficiency in users endpoint using search => **

(props @joehoyle, #2722)

Ensure the terms list is a list

(props @joehoyle, #2724)

Added @return on handle_featured_media() doc

(props @vishalkakadiya, #2725)

#2730 Update attachments fields added with register_rest_field

(props @BE-Webdesign, #2731, #2730)

#2582 Ensure the roles property is always an array

(props @BE-Webdesign, #2728, #2582)

Move post_password_required filtering to preparation

(props @rmccue, #2735)

Use wrapper for sanitize_title to avoid messed up slugs.

(props @joehoyle, #2723)

Force per_page to override the filter variable

(props @rmccue, #2699)