Return to handling site mismatches cleanly

A hack was implemented to handle site mismatches outside of the
core script due to the use of an outdated version of Pandas. This
should return the code to it's original form and behavior and
remove additional scripts and intermediate datafiles that were
added as part of the hack.
Merge pull request #2 from weecology/match-sites-cleanly

Return to handling site mismatches cleanly