This is a backport of all check_log updates from master, particularly the move from a perl script to a python script in !27839 (merged) and various pattern updates like !24401 (merged).
The changes to check_log.pl/.py were simply done by:
git checkout upstream/master -- Trigger/TrigValidation/TrigValTools/bin/check_log.pl Trigger/TrigValidation/TrigValTools/bin/check_log.py
so this is not new code, just a sweep.
