Comment 6 for bug 1282751

Fix pushed:

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/berick/lp1282751-cc-payment-rounding-error

Note that I could have accomplished the same thing by simply removing the int() calls in the summing routine (with fewer code changes), but in this case I thought it was worth it to leverage the fpsum() utility function to help reign in the proliferation of floating point summing code. Plus, I think it's slightly more readable.

To test:

1. Create a single grocery fine on a patron account for 8.29.
2. As the patron, log in to the catalog, then change the URL to https://EVERGREEN_HOST/eg/opac/myopac/main_payment_form -- It's not necessary to have CC payments enabled to view this page.
3. Confirm the total amount to pay is $8.28 before the above patch and $8.29 after the above patch.
4. To further test, add more fines and payments and confirm amounts correctly add up in the same interface.