Otherwise, setting Reporter::errors_to_stderr=F causes important
error messages to be lost (and this setting is the default for
ZeekCtl). E.g. now that we terminate if there's errors during
zeek_init, GH-369 shows that the only error message given was
"fatal error: errors occurred while initializing", which is not
helpful in determining the actual issue.
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
