DSR - Fixed discrepancy report and updated drupal queries to use commerce tables

## Bugs
 - Changed a broken $salesforce->query() call in the discrepancy reports because it was expecting a soql object but we were passing a string. I changed the call to $salesforce->apiCall(...) as is done in other areas of this module.
 - Initialized an orders variable to prevent notices when no orders match the given criteria on a report query.
 - Changed the drupal queries to use the commerce tables instead of the fundraiser_donation table. Now the queries look at the transaction date.
 - Fixed sfid lookup for the discrepancy report.

## Potential Bug
 - Adjusted query date format for drupal queries to use MySQL's from_unixtime() format. This may have caused issues with the boundaries on the date range query but I wasn't able to cause that behavior.

## Extras
 - Added some very basic DSR tests.
 - Removed an unused template file and repaired dsr_theme() and related theme functions.
 - Lots of coder cleanup in the comments.
 - Added some deprecated docblock tags for possible later removal of unused code.
 - Removed an empty file that wasn't included anywhere.

This is the correct way to theme this so it'll take on any theme overrides.