TDVT 2.2.0 - Use envvar for tabquerycli path
TDVT will now first look for the environment variable TABQUERY_CLI_PATH when starting a test run. If the envvar exists and there is an executable at that location, TDVT will run tests using that tabquerycli. If not, it will follow current behavior and look at the tdvt_override.ini file for tabquerycli's location.