Single, clean, unified salary data file

I have created a single, unified CSV file of salary data, bart-comp-all.csv.

This file has all the same rows as nonmgmt.csv and mgmtnopolice.csv (with a "Source" column to identify the source file of each row).  This file also has 'Job Family' and 'Union' columns based on manually cleaning and mapping all of the job titles in the original data set.  Detailed notes on the methodology outlined in comp-data-cleaning-notes.txt.

Strongly recommend using this as the single source of salary data and getting rid of all others to avoid confusion.