Bug 16272: Automatically switch an on-site checkout to a regular checkout when checke...

Bug 16272: Automatically switch an on-site checkout to a regular checkout when checked out

Use case: A patron checks some items out on-site and want to take it home.
To facilitate the librarian work the checkout is directly switched from
on-site to regular when checked out if the new pref SwitchOnSiteCheckouts is on.

Test plan:
0/ Let the new pref SwitchOnSiteCheckouts off
1/ Checkout one items to a patron and tick the "on-site checkout"
checkbox
2/ Check the same item out without ticking the "on-site checkout"
checkbox
=> You should get "This item can not be renewed, it's an on-site checkout"
3/ Switch the pref on
4/ Repeat 2
=> The on-site checkout should be automatically switched to a regular checkout

Sponsored-by: BULAC - http://www.bulac.fr/
Signed-off-by: Nicolas Legrand <nicolas.legrand@bulac.fr>
With small changes to apply to master.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>