Add a command line option --log-fatal-domains= and environment variable
WIRESHARK_LOG_FATAL_DOMAINS that aborts the programs if a domain in
the list is logged to.
Negative matches for fatal log domains not implemented for now,
pending a relevant use-case.
Add docs/diagnostic-options.adoc, which is a snippet that documents our
various --log-* options. Include it in the dumpcap, rawshark, and tshark
man pages.
Make the ws_log_print_usage output more consistent.