Bug 22650: Prevent multiple holds on individual items

Bug 22650: Prevent multiple holds on individual items

This patch corrects a missing id on the holds_to_place field and adds code to disable the box when an item is checked

Additionally script login now places a single hold if an itemnumebr is passed and checks for holdability of the specific item

To test:
 1 - Allow multiple holds per record in circ rules
 2 - In staff client, go to place a hold on a record
 3 - Select a patron
 4 - Increase the number of holds
 5 - Then select a specific item to hold
 6 - Patron now has multiple holds on a single item
 7 - Apply patch
 8 - Repeat, notice that count is disabled when item checked
 9 - Confirm count is enabled when 'Hold next available item' is checked
10 - Set number to more than 1
11 - Check an item and submit
12 - Confirm only one item is reserved
13 - Hit the script directly (with valid info):
     http://localhost:8081/cgi-bin/koha/reserve/placerequest.pl?biblionumber=1&checkitem=1&holds_to_place_count=2&borrowernumber=5
14 - Confirm only one hold is placed
15 - Confirm multiple hits of the url do not generate further holds

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>