update call args to output_for_bill in update_bill_version_list

I broke this on July 5, 2013 in 4dbe3386a0f0b463bb125ee289027dbc4c6b95d8.

Fixes #103, and part of #113
don't try to use wget to download from FDSys if wget isn't available

If the system doesn't have wget, was broken by 9b01c418c2c29e14c4a25903396a856b27ec9b42.

Hopefully fixes the second issue in #113.