This allows Zeek execution to continue gracefully in the presence of such
errors, particularly at zeek_init() time. Includes a tweak to expand the
bifs.directory_operations test to check continuation after errors.
Resolves#3595.
This also installs symlinks from "zeek" and "bro-config" to a wrapper
script that prints a deprecation warning.
The btests pass, but this is still WIP. broctl renaming is still
missing.
#239