* All "Broxygen" usages have been replaced in
code, documentation, filenames, etc.
* Sphinx roles/directives like ":bro:see" are now ":zeek:see"
* The "--broxygen" command-line option is now "--zeexygen"
This is a fairly straightforward change. Previously, users had no
control over whether this script was loaded. By relocating it to
policy, users can now choose whether or not this is necessary
functionality without modifying core Bro scripts.
