StripeController: handle case where description is None.
StripeController: fix typo in cancel_subscription.
GoldPaymentController: secret code must be unique.

create_claimed_gold attempts to create a row in the gold table and
will fail if secret is not unique.
Store stripe customer id in Account.gold_subscr_id.

We need to do lookups of Account by stripe customer id and
gold_subscr_id has an index. Previously was using a new attribute
stripe_customer_id which didn't have an index and lookups were too
slow.
StripeController: handle exception when customer isn't found.
StripeController: handle charge.failed with insufficient information.
ProfileBar: attribute is 'paypal_subscr_id'.
StripeController: don't cancel subscription if the charge was attempted.
Don't allow multiple gold subscriptions.
Gold: redirect to subscription page if use tries to resubscribe.
get_total_run: Fix handling for house campaigns.
PromoteReport: PromoCampaign end_date is not inclusive.
analytics: run on comments pages for promote links.
StripeController: don't raise exception for recent charges.
GoldSubscription: use correct check for paypal subscription.
StripeController: add handling for charge dispute events.