Regression Fix: Make Squid abort on parse failures.

Regression Fix: Make Squid abort on parse failures.

The addition of multi-file parsing and catching of thrown errors between
them caused any errors in sub-files to be non-fatal and allow Squid to
run as if everything was normal, even if parts of the config were not
being loaded.

Squid will now propigate the error exception out and exit with a count of
the errors found.

The main() safety wrapper from 3.1 has also been ported to catch some
unwanted crashes.