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
Add collapse_deleted_comments to API/modlog
Add link to /gilding.

	Add full link and descriptive IDs.

Remove status margin for button padding.
Increase line-height for collapsed comments.
report reasons: Focus on text input when "other" is selected.
Move gold_expiration calc into separate function
Add admin tool to adjust months of gold for user
JS Styleguide updates for adminbar.
Revert "Revert "Send 1% of RUM tracking calls to hivemind""

This reverts commit d5131233e3ea6ba3d55189ccc196f14deabdc2f5.