* 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
before. In the API, attachments now can be either image, video or gifv. Gifv
is to be treated like images in terms of behaviour, but are videos by file
type.
application website validation, don't link to app website if website isn't set,
also comment out animated boost icon from #464 until it's consistent with non-animated version