Support env variables in config and profile

This MR adds the ability to specify environment variables in analysis config.yml files, and in the site profiles, which will then be added to the "environment" line of the condor submit files for all jobs. This MR also updates the profiles to move a variable from the directive section to the new environment section.

Previously, the only way to add environment variables automatically was to use a custom profile, or to use getenv=True.