Currently load_theme_functions is not being called when a post's type is "page". This is resulting in the post_tag taxonomy not being registered as a post type on themes that support tags for pages. https://[private link]

Merges r142741-wpcom.

In r142741 I enabled load_theme_functions for type=page.  Today we had a report of issues with the page listing in calypso for the Portfolio theme.  Confirmed the regression was introduced with the loading of theme functions so am backing out that change to investigate further.  https://[private link]

Merges r143168-wpcom.

wpcom check for filter that uses wpcom-specific callback fn

Merges r131587-wpcom.

…n Jetpack

In r131418 and r131419 I updated a couple of endpoints with new versions. To reduce code duplication, I used late static bindings.
Unfortunately, that's only in PHP > 5.3, and Jetpack should be compatible with 5.24+

This changeset uses wp filters as a workaround. Less elegant, but it works.

Merges r132024-wpcom.

Merges r132099-wpcom.

…nd also return just a count of published posts.

post_count calculation is the slowest, the hand crafted query doesn't directly hit and index (the index is on type,status,date) and so can sometimes be slow.
Have seen upper times of over 4 seconds and the 5minute median is 3.3ms and is the slowest part of the response building for a site.

Merges r132149-wpcom.

The post count in the changeset being reverted resulted in incorrect counts. This caused bugs with Stats, among other things.

See: https://[private link]

Merges r132162-wpcom.

…s been tweaked

See: https://[private link]
See: Automattic/wp-calypso#3848
See: https://[private link]

Merges r132219-wpcom.

As part of ongoing efforts to make Jetpack sites easier to manage in Calypso,
we are synchronizing more data and trying to make WPCOM responses more
accurate.

This change lays the groundwork for that by splitting out Jetpack and shadow
 site customisations.

Merges r132364-wpcom.

Merges r132389-wpcom.

…dpoint

This restructures how sites are rendered in the API so that we can return less
data without incurring the cost of generating that data.

Merges r132485-wpcom.

Since WordPress 4.7 actions array is no longer an array, but an object that inherits ArrayAccess.

Change wp_get_attachment_url for get_attached_file to avoid breaking API responses on VIP sites.

Sync from wpcom r156638

…oints

Removed old publicize endpoints that are no longer used.

Authored by: Ben Lowery <@blowery>
Summary: This teaches the get_post_by function how to build up a post object using the fields query parameter. Instead of building the entire post object and then filtering out the unwanted parts later, we only build up the parts of the post object required by the API call. If no parameter is specified, the entire object is built and returned, just as now.

Test Plan:
Install patch
Try requesting /sites/:site/posts, /sites/:site/posts/:post, /read/sites/:site/posts, /read/sites/:site/posts/:post with fields specified and unspecified.

Reviewers: dmsnell, bluefuton

Subscribers: samauri, dmsnell

This merges r156885-wpcom.