Carousel: Switch slide when pressing back/forward buttons

Before this change, the browser's back and forward
buttons would update the URL with the ID of the
desired slide, but the UI would not actually
update.

The problem was that the `open` method was getting
called for `onhashchange` events, but it would do
nothing if the carousel was already activated.
This patch adds a new method that will switch the
slide even if the carousel is already open.
Add v2 heartbeat data.

This should break history so old over-common data isn’t clouding up
coronet stats.
Snag the core and php branch as well.

This will combine all the point releases into a single stat for more
readable detail.
Carousel: update carousel presentation when viewport size changes

When the browser viewport changes, either because the browser is resized or because the device orientation changes, the Carousel's display should be updated to best conform to the current viewport.

Fixes #6306. Props rads.

Merges r94673-wpcom.
Merge commit '83305a9'

Conflicts:
	modules/carousel/jetpack-carousel.js
* Reduced the redundant storage of data. Eliminated _feedback_author, _feedback_author_email, _feedback_author_url, _feedback_subject, _feedback_ip, _feedback_contact_form_url, _feedback_all_fields and reduce _feedback_email to just hold just the email message the email recipient(s).
* Added a check for X-akismet-pro-tip header and discard spam when it's recommended, similar to latest version of akismet plugin.

Merges r94591-wpcom.
Avoid warnings after r94591.

Merges r94703-wpcom.
check for discard header first, return wp_error if found so that spam response is ignored. If not found, check to see if spam comment

Merges r94827-wpcom.
New Sharedaddy: Add tiny top padding to Sharedaddy container, so if the last element in an entry is an item without a bottom margin, Sharedaddy doesn't place itself right next to it.

Merges r94588-wpcom.
social links: mini refactor

* clean up an if statement
* move all admin-only code to a dedicated function that bails if not in the admin or the current user is not authorized to make changes
* only check/refresh the options when a publicize setting is changed, this fixes a bug where options would get cleared when they shouldn't

see http://[private link]

Merges r94762-wpcom.
Open graph: when grabbing the thumbnail of a post for use as the OG image, resize it if it's bigger than 1200 pixels which is Facebook's recommended size.

See https://[private link]

Merges r94558-wpcom.
Gravatar: allow certain HTML when displaying Gravatar profiles via widget / shortcode.

Currently, they were using either wp_kses_data, which in most contexts strips all HTML or esc_html, which encodes HTML. Neither were ideal. We're now using wp_kses_post instead to allow more HTML in profile descriptions/bios.

http://[private link]
https://[private link]

Merges r94331-wpcom.
Shortcodes: allow Google Mapengine support with the [googlemaps] shortcode

http://[private link]

Merges r94839-wpcom.
Shortcodes: add some inline usage examples for the googlemaps shortcode

Merges r94840-wpcom.
Carousel: update carousel presentation when viewport size changes

When the browser viewport changes, either because the browser is resized or because the device orientation changes, the Carousel's display should be updated to best conform to the current viewport.

Fixes #6306. Props rads.

Merges r94673-wpcom.
Merge commit 'f486708'
JSON API: Trap more specific comment submission errors.

comment_duplicate and comment_flood

http://[private link]

Merges r94571-wpcom.
Merge commit '35413e3'
Widgets: adjust the regex and validation used to validate the hex of the colors used in the twitter timeline widget so that it supports uppercase and 3 character hexes properly.

see https://[private link]

Merges r94565-wpcom.
Merge commit 'c1d4ebc'