When a text with an (escaped) zero byte was passed to ParseValue, only
the part of the string up to the zero byte was copied, but the length of
the full string was passed to the input framework.
This leads to the input manager reading over the end of the buffer.
Fixeszeek/zeek#1398
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