Bug 14435: Add the ability to store result's report

Bug 14435: Add the ability to store result's report

At one time it was possible to store the results of a report into the
saved_reports table.
This allowed the librarians to compare different results, from the Koha
interface.

This patch is a proof of concept and is not very polished (understood:
it cannot be pushed like that).

Test plan:
Execute the runreport.pl cronjob script with the new --store-results
option.
This will serialize into json the results and put it into the
saved_reports table.

On the "Saved report" list, the "Saved results" column is now populated
with a date (note that you can have several date for a given report).
If you click on this link, the data will be displayed in a simple table.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Katrin Fischer  <katrin.fischer@bsz-bw.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>