Add Custom Content Type

Add module for Custom Content Types and Portfolio CPT
Add Portfolio Shortcode CSS

Add default styles for portfolio shortcode
Remove AIOSEO

As per conversation with @georgestephanis
Alphabetical sort of conflicting OG plugins
Alphabetical sort of conflicting Twitter cards
Remove Yoast; add comment re our filter
REST API: Writing method must be accessed via POST
REST API: oops...this one too.
Merge pull request #828 from richardmtl/conflicting-og-cleanup

Conflicting og cleanup and alpha sort
Top Posts: Strip HTML from post titles

Prevents tags from being output along with the rest of the title:

https://github.com/Automattic/jetpack/issues/525
Merge pull request #873 from aheckler/master

Top Posts: Strip HTML from post titles
REST API: Modify plugins endpoints path.

Instead of
`/sites/:site_id:/plugins/:urlencoded_plugin_filename_without_dot_php:/<
action>/`, use : `/sites/:site_id:/plugins/<action>/ POST { plugin_id:
plugin_filename }`.

Adds simplicity to the path and flexibility for future bulk actions.
REST API: Fix endpoints path comment.
REST API: Modules: Stricter response format.

Adds more control over the information returned about each module.
REST API: Fix example request data.
REST API: Remove code tag ¿¿¿???
My Blogs Post Editor: Add Preview button. Add revision support to API.

Merges r101435-wpcom.
Likes: update the Settings > Discussion > "Someone likes one of my posts" toggle to appear enabled by default.

This feature is already enabled by default, but this option made it appear as though the feature is disabled
in certain situations. On blogs where the settings on the Discussion page haven't been updated (e.g. a new
blog), the absence of a saved value for this option was causing the Likes notifications to be sent -- even
though this option appeared disabled on the admin page.

https://[private link]

Merges r101245-wpcom.
Publicize: allow html entities to be part of the messages sent to services without allowing actual html tags

Standardize the way we sanitize the messages sent to services into a single method `Publicize_Util::sanitize_message`, which first removes `script` and `style` tags, then runs the content through kses, trims whitespaces and decodes any left over entities.

This allows users to have hearts and other symbols in their publicize messages. This is a redux of [101294] which was reverted in [101468] because it was causing html to be displayed in publicized posts.

The following code has been tested to ensure that the problems from before are no longer present.

see https://[private link]
see https://[private link]

Merges r101489-wpcom.
Sharing Services/Shareddady: remove support for Digg who's API no longer works

see https://[private link]

Merges r101457-wpcom.