Comment Votes: update CommentSortsCache *after* updating comment scores.

This was causing CSC to have scores based on stale (off-by-one) vote
data.

One thousand thanks to @raldi for noticing this.
prefoptions: Update "volunteer to translate" link.

This is deliberately an absolute link so that open-source installs will
contribute back to the main i18n repository.
reddit_base: Exempt all 5xx responses from pagecache.
Add confirmation to unsaving
Split rising out of new to its own tab

Also redirect any requests for the old rising URL to the new one

Redirect POST requests to GET (should only be necessary during push)
Display default thumbnail on deleted or removed links.
Add body classes to all remaining subreddit pages
Remove alternate labels for tabs when they're the active one

(This hasn't worked since April 2012 anyway)
Send message to link submitter when a top-level comment is distinguished
Prevent incorrect redirection when visiting /r/subreddit/new?sort=rising
Re-add listing-page class to body classes
Confirm suggest title if they already entered a title
Don't trim off over half of a suggested title
Have save/unsave button toggle back and forth

This also removes the confirmation added in 3e74406
front.py PEP8 whitespace cleanup
Exclude items hidden to the user from 'other discussions'

Exclude from both the listing as well as the count in the tab
Add distinguished status to JSON templates
Avoid loading pycountry in the app.

It takes a tonne of memory. If the countries.json file is present
(generated by "make countries") then the app will prefer to use it
saving itself megabytes of space.
Fix permission control in the moderator invitation form.
Make ModList narrower and remove sendmessage col.