WebSubmit: use PyPDF2 if available

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
BibSched: increases size of monitor columns

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
WebApiKey: renames unit tests to regression tests

* The tests were modifying the database thus have been renamed.
  (closes #1324)

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
WebSearch: SPIRES date math search fixes

* Fixes treatment of the first day of the month in SPIRES date queries
  like "find date 1976-04-01 and t dog".  (closes #431)

* Fixes "this week" and "last week" date search functionality.

* Accepts two digits for year search so that users can type 78 instead
  of 1978.  (closes #948)

Reviewed-by: Samuele Kaplun <samuele.kaplun@cern.ch>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>