For Gaz_counties_national_V2_1.txt:
  * removed unwanted spaces in header
  * removed "$" in last two columns
  * last two columns are in whole dollars (no decimal)

For cis_435_travel_mail.py
  * corrected for NHTS_2009_transfer_US.txt
  * corrected for Gaz_counties_national_V2_1.txt