[new] sysutils/web2ldap and co

Hello,

Here are three new ports, two deps, and the one piece de resistance,
web2ldap.

sysutils/web2ldap - web-based LDAP client
devel/py-xlwt - dep for exporting LDAP query results as XLS files
devel/py-ldap0 - web2ldap's interface to the OpenLDAP libraries

The author of web2ldap and py-ldap0 has been very responsive to some
questions I had a few months ago and accepted a change to make it
easier to manage on the BSDs as a whole.

More information here: https://web2ldap.de/
Project upstream here: https://gitlab.com/ae-dir/web2ldap

I've been using this in my own tree for several months now with no
issues. That being said, I hope I didn't get complacent in the
submission.

Completely understand if this is too niche to warrant being included in
the tree. If not so terribly niche, feedback?

Thanks,
Lucas