New Task module for rotating transaction data. Principal differences:
* Only rotates data older than the current day. Can be run repeatedly
  or at any time of day without issue.
* Uses DTransactionsModel to create monthly views if needed rather
  than maintaining a separate view definition. Does not bother creating
  deprecated rp_ views for each month.
* Rebuilds summary tables for each day so there are never primary
  key errors or missing data.
* Does not support remote archiving. That whole feature could probably
  go away.
Deprecate old fannie-side receipt views that aren't used
BUGFIX: incorrect column name in equity history task
Reduced prodExtra usage in favor of products.brand
Built-in code update mechanism. Alpha. Be careful.
I ripped the old, non-model database update out of the UI entirely
and added this so the updates tab handles both data and code.
I updated the documentation to reflect this.
I also added a key/value store mechanism to the DataCache class
previously used for caching report data.