Add CSRF protection to /api/givecreddits
Gilding: track "proxy gildings" in secret column
Show banned/deleted state with header style
Don't hide report button for mods/admins
Show reports made by mods and users separately

This makes reports by moderators non-anonymous, and shows the name
of the moderator before their report reason. In addition, it shows the
number of reports with each reason for user reports, and orders them to
show the most common ones first, instead of the previous behavior of
arbitrary ordering (and possibly even not including the most common
reasons if there were a large number of different reasons).

This commit also adds a temporary deprecation warning for report_reasons
in the API, which should be removed in a month or so.
Collapse deleted/removed comments.
Make a subreddit setting to collapse children of deleted comments.
Move timings out of adminbar.
Remove all pretense of button voting actually working.
Add support for tuples of types to ConfigParse
Add retina-ready thumbnails
HiDPI: Images > 70 and < 140 width use non-hidpi dims
Add Twitter Card support

[Twitter Cards][0] are little snippets of information that get displayed in
Twitter's feed when a message includes a link.  This pull adds a few meta tags
to enable this, similar to reddit/reddit@027504a's work for Facebook.

While there is [a Twitter Cards validator][1], it requires pulling the page
itself, which makes this difficult to test.  We also have to make sure to run
it through the validator to get approval before it goes live; it's unclear if
this acceptance process is automated.  The code that adds the Card is protected
by a feature flag to help with this.

There are [some restrictions][2] on filesize for images, but I don't
think we want to deal with that one, at least not yet.

[0]: https://dev.twitter.com/cards/overview
[1]: https://cards-dev.twitter.com/validator
[2]: https://dev.twitter.com/cards/markup
trunc_string: split on word boundaries

This makes it so that instead of seeing text like this:

    This is a long tit...

we'll get

    This is a long...

when truncating "This is a long title".  Usually this is just a minor
improvement, but occasionally odd truncation can [lead to hilarious
results][0].  And, y'know, I don't like hilarity.

We currently only use `trunc_string` in a few places, all related to the
displayed titles or descriptions in Facebook OpenGraph notes or Twitter Cards,
so the impact isn't too terribly great.  We are now including the suffix in the
length count, so that might actually fix a bug.

We don't use the `length` parameter by keyword anywhere, so changing it isn't a
problem.

[0]: http://blogs.hbr.org/2012/07/i-wont-hire-people-who-use-poo/
OpenGraph/Twitter summaries: don't show nsfw thumbs

When creating OpenGraph (Facebook) and Twitter summaries of comments pages,
we provide a link to a thumbnail for them to embed.  However, we probably don't
want to do that for NSFW posts, so now we don't.
Add og_data for subreddit link pages
Twitter Cards: always show subreddit name

After looking at some usage with real posts, we determined that subreddit names
are pretty important.  So, we'll always show them now, and truncate the post
title accordingly.

Although subreddits can have fairly large names (20-something characters), most
of them don't, so in practice we shouldn't be cutting off much of the title.
Even in the worst case, it won't be so bad.

For a submission entitled "I don't even know how to describe the stupidity in
this gif...", before:

    I don't even know how to describe the stupidity in this gif... •...

and after:

    I don't even know how to describe the stupidity... • /r/reddit_test7
Reports:  Fix crash if 'things' is empty
ProfileBar: show creddits even if user not gold
Report: don't hide if reporter is moderator/admin