support for EC2 IAM roles with Amazon S3 file store/backup
refactor multiple instances of S3 key check logic to single variable
Pass rejection message along in rejection mail if present
FIX: flag count displayed at wrong position
OPTIMIZATION: Add index to `post_timings` and adjust the query
FIX: helpful/flagged posts styling on mobile
Start making better-written tests for the email job
Refactor out handle_failure method in PollMailbox
Attempt at checking throws....
FIX: don't let admins skip post validations, unless it's faq, tos, or privacy
FIX: styling of bouncing validation errors in composer was broken
Add more tests, undo some changes to fixture files

Was causing Email::Reciever tests to fail
Revert bad diff
FIX: Topic progress bar was not updating after expanding gaps
OPTIMIZATION: Don't run 12 queries every 15 mins for the Top section.
Instead, run the daily queries once every hour, and the reset of the
queries once a day.
Merge pull request #2615 from riking/stream-len-prop

FIX: Topic progress bar was not updating after expanding gaps
Merge pull request #2614 from riking/email-tests

Email tests, and include posting error reason
TESTS: Remove `URL_FIXTURES` constant for pretender
TYPO: Missing comma
FIX: don't validate topic title if it isn't changing. topic stats were failing to update, causing necro topic warnings and other problems.