Now using the original text form of @-mentions and #-tags, as in Twitter's own HTMLification.
Canonical forms are still used in generating links, where it's polite to match the canonical form.
Should fix issue #3027: twitter user avatars not getting imported.
Due to the change in URI, all twitter users that had been previously seen were getting new profile entries, which tried to save the same avatar. This would fail as Avatar.url has a unique index.
Note: now anything new seen in the last couple days in production will still potentially conflict.
This option may be useful for intranet sites that don't have direct access to the internet, as they may be unable to successfully fetch those resources.
