Bug 11759: Batch checkout - Add the new template

Bug 11759: Batch checkout - Add the new template

This patch is the main patch.
It adds:
- the new template circ/circulation_batch_checkouts.tt
- the change into circ/circulation.pl

=== Why this feature is useful for some libraries? ===

Currently Koha does not allow to checkout several items at once to a
user. This can cause a waste of time when a user want to checkout more
than 10 items.

This development has been asked to have statistics on in-house use.
Every night, a librarian will enter a barcode list (from a file or a
scanner : the librarian scans the barcode of the documents that users
let on the tables). Barcodes will be added to a statistics patron in
order to count the number of items consulted.

The development has been expanded to cover another need: some special
libraries (BDP for "Bibliotheque departementale de pret": "Loan Regional
Library").
These libraries loan items to smaller libraries (municipal). The number
of items could be very important and the current way offered by Koha is
not adequate.

=== Test plan ===
0/ Apply all patches and execute the DB change entry.
1/ Verify you are abble to do some checkouts (with confirmations,
errors).

= Statistics way =
2/ Create a statistical patron (e.g. category code STATS).
3/ Update the batch_checkouts pref with the category code (STATS).
4/ Go on the member page and verify the new "Batch check out" tab
appears (and only for this user).
5/ Check some items out on the new page using the textarea or a file.
6/ Verify the table contains the item's information and the
"Information" column contains "Local use recorded".

= Real checkouts =
7/ Create a non statistical patron and update the pref.
8/ Check some items out on the new page using the textarea or a file.
9/ Verify the information in the table is consistent.
10/ Verify item without confirmation needed or impossible alert is
checked out.
11/ If the logged in user has the "force_checkout" permission, all
checkouts with a "confirmation needed" message can be done.
If the logged in user does not have it, there is no way to force the
checkout.

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>