Carousel: Add extra whitespace below some icons in sprites to prevent image bleed

Fixes #6375

Merges r92658-wpcom.
Optimize images

Merges r92734-wpcom.
Props wpcom user @optimizerbot.
Remove themedevp2 url visible in Jetpack
http://[private link]#comment-6905

Merges r84364-wpcom.
Merge commit '25420d0' into wpcom-merge
Custom Post Types: Testimonials: Declare static functions.

These were kicking errors like:

{{{
Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method Jetpack_Testimonial_Title_Control::sanitize_content() should not be called statically in /Users/bengillbanks/Documents/mamp/wordpress-themes/wp-includes/plugin.php on line 199
Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method Jetpack_Testimonial_Textarea_Control::sanitize_content() should not be called statically in /Users/bengillbanks/Documents/mamp/wordpress-themes/wp-includes/plugin.php on line 199
Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method Jetpack_Testimonial_Image_Control::attachment_guid_to_id() should not be called statically in /Users/bengillbanks/Documents/mamp/wordpress-themes/wp-includes/plugin.php on line 199
}}}

See: http://[private link]

Merges r89070-wpcom.
Merge commit '5c24ce2' into wpcom-merge
Nova Menus: Hack day improvements with @melchoyce
* add custom icon
* 'all menu items' admin: UI/style cleanup, display featured image if set
* 'single item' admin page: edit title input label, add description to 'menu item labels' meta box, edit update messages
* 'add many items' admin page: add 'new row' button, style cleanup
* consolidate admin styles

Merges r87047-wpcom.
Nova Menus: add menu item count to dashboard 'at a glance'

Merges r87066-wpcom.
Featured Content: Hide term based on term name rather than term id.

Since only the term name gets updated by the Customizer, the term_id will not
always be correct during preview. This might lead to confusion when the
previewed term is still visible, even though it is supposed to be hidden.

See #themes2208 for original report.

Merges r90228-wpcom.
Merge commit '71f5903' into wpcom-merge
Grunion: Properly quote the name in the From and Reply-To email headers so that commas in names don't confuse parsers.

Fixes: http://[private link]

Merges r90605-wpcom.
Merge commit '8707395' into wpcom-merge
newdash usercentric posts: This commits our work-in-progress code for the usercentric posts page

This commit should not impact anything in production, other than to create a new /posts page that is enabled for tritonites, which will have different styles applied, taken from the newdash-static repo. If this commit affects anything else, it should be reverted.

I am adding a temporary rest api endpoint for /me/posts which uses several mysql queries to pull posts from all blogs user is a member of. This endpoint will be rewritten to make use of elasticsearch when some backfilled data becomes ready. Also adding a /me/comments endpoint, but it's just a stub for now... little more than a copy of the /me/posts endpoint. Adding in styles from the newdash-static github repo, and reorganizing the /h4/tabs/functions.php file to separate the style and script enqueue statements so we can more easily isolate the css for the usercentric pages.

Merges r92695-wpcom.
REST API

Support uploading media via URLs (sideloading) and not just by passing file data.

Merges r93005-wpcom.
Reblogs: bust cache for [89596] and add a little js to handle button clicks

Merges r89597-wpcom.
Reblogs: bust cache

Merges r89601-wpcom.
Reblogs: bust cache for [89604]

Merges r89605-wpcom.
Reblogs: bust cache for [89610]

Merges r89611-wpcom.
Comment Likes: Makes the option for enabling Comment Likes available to A12s and anyone on a sandbox.

DO NOT MERGE WITH JETPACK. This is a temporary changeset (until we can fully launch Comment Likes, and should not be merged because it contains a call to is_automattician(), which doesn't belong there).

Merges r89708-wpcom.
Reblogs: bust caches for [89739] and [89741]

Merges r89743-wpcom.