Bug 5786 - Move AllowOnShelfHolds and OPACItemHolds system prefs to the Circulation...

Bug 5786 - Move AllowOnShelfHolds and OPACItemHolds system prefs to the Circulation Matrix

C4::Reserves:
* Added OnShelfHoldsAllowed() to check issuingrules
* Added OPACItemHoldsAllowed() to check issuingrules
* IsAvailableForItemLevelRequest() changed interface, now takes
  $item_record,$borrower_record; calls OnShelfHoldsAllowed()

opac/opac-reserve.pl and opac/opac-search.pl:
* rewrote hold allowed rule to use OPACItemHoldsAllowed()
* also use OnShelfHoldsAllowed() through
* IsAvailableForItemLevelRequest()

templates:
* Removed AllowOnShelfHolds and OPACItemHolds global flags, they now
  only have meaning per item type

Signed-off-by: Nicole C. Engard <nengard@bywatersolutions.com>
I have tested this patch left, right and upside down for the last
several months. All tests have passed.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>