Fixed DSR discrepancy report bug and a potential date range bug

## 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.

## 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.

There is some halfway done code in this module that almost started on using literals for the drupal side. Doesn't seem like it got very far.