* For undownloaded attachments, set type :unknown, display them as a list in the web UI

* Fix case when attachment type is set explicitly

* Add FR locale for the onboarding modal component

* Slightly increase the max-width and max-height of the onboarding modal

This is done so it doesn't break with locales whose strings would be
too long

* Update FR locales for onboarding upon PR comments

This is necessary for boosting long posts on small screens - see this post for video: https://slime.global/@masklayer/102308

* Basic onboarding modal that's shown to users once

* Lay out pages 2 through 5, add images, style modals (#1509)

* Lay out pages 2 through 5

Added images and laid out pages 2 through 5 in the jsx file. SCSS will
come, still working on just seeing if this works at all.

* Fix jsx errors, add images to modal pages, style modal pages

* Add animations to onboarding pager changes, improve wording and styling

* Finishing touches on the onboarding

* Add missing propTypes

* Update wording

This may address the scrolling issues mentioned here: https://github.com/tootsuite/mastodon/issues/1622

* Improve emoji picker look

* Add hover animation to emojis in picker

* When avatar/header are GIF, generate static versions.
Account API returns "avatar"/"avatar_static", "header"/"header_static"
Static version is the same as original for other cases
Web UI de-animates avatars in toots, lists of users

Fix #441, fix #596, prerequisite for #1064

* Fix JS test

* Add rake task to generate static avatars/headers from GIF ones, add test

Addresses #1451 which notes the emoji picker is too light. I agree, so I submit this adjustment.

Changes:
Changed the background to a darkened version of another system color

* Replace column margin with padding

This improves horizontal scrolling behaviour significantly; scrolled flex elements are... a little weird.

* Move clear column button styling to css

Fixes icons and emoji size issues described in #1233.

Use nicer scrollbars in MS edge

The Mastodon mascot was previously anchored to the bottom, and that was since broken. This restores that behaviour!

It also disables the double-scrollbar behaviour that was caused by this area allowing overflow-y in addition to its parent doing so.

word-break:break-all is a surefire way to break things. It should be set
to normal.
This merge just set it back to what it should be.
Tested on Firefox 52.0.2 and Chrome 56.0.2924.87 with no detected
errors.

Thanks garg

Privacy descriptions were very difficult to reason. This is the minimal level of color contrast to be WCAG AA compliant.

add ability to open status by URL from search (fix #53)

loaded status; do not preload submitted statuses into community/public
timelines, unless those timelines have already been loaded; do not
close streaming API connections for community/public timelines, once
they have been established (most users navigate back to them eventually)

from zooming in on them