This is a big commit. A bit too much really. Mercury fish tissue analysis and stations locations updated. An error in the exclusion of NA results from WQP was corrected and resulted in MORE stations to locate. Added station category assignment. Began looking at relating to ARS but need updated names with Criteria_Pollutant_Lookup. A couple files karla added for tracking issues.
Merge branch 'master' of github.com:petertbryant/ToxicsRedo