Bug 7673: add syspref in sysprefs.pl

Bug 7673: add syspref in sysprefs.pl

Also fix a typo in the permission description

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Patches pass QA script and tests.

Copying the test plan from the bug report:
Test plan:
1/ add the following permissions to the logged in patron:
edit_item, edit_items_restricted, delete_all_items,
items_batchmod, items_batchmod_restricted

2/ Fill the prefs SubfieldsToAllowForRestrictedEdition
and SubfieldsToAllowForRestrictedBatchmod with some
subfield (for instance "995$f 995$o" and "995$o")

3/ Verify you are allowed to edit the item fields defined
in the pref SubfieldsToAllowForRestrictedEdition.

4/ Try to edit item in a batch and verify you are allowed
to edit the item fields defined in the pref
SubfieldsToAllowForRestrictedBatchmod.

5/ Try to delete all items of a record

Play with the pref/permissions and verify they are
correctly taken into account.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>