Bug 19919: Stop using paidfor altogether

Bug 19919: Stop using paidfor altogether

This patch removed references to setting and getting the items.paidfor
field. Where it was used for display, in moredetail.pl, we replace it
with a query on the accountlines.

Test plan:
1) Apply patch
2) Pay off a LOST item
3) Check for the associated display of 'Paidfor?:' on the itemdetails
page
4) Writeoff a LOST item
5) Check that a 'Paidfor?:' is not displayed on the itemdetails page.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>