Submitted and fixed bug #119001

[Daniel Hannum]

This fixes what I consider to be the worst bugs in the mortgage/loan
repayment druid: errors where it makes payments of the wrong size or
wrong time, or makes the wrong number of payments. The other things I
plan on doing are mostly adding functionality.

http://bugzilla.gnome.org/show_bug.cgi?id=119001

I attached a patch to the bug. As I've never done this before... did I
do it right?

dan