fold deployment::vars into mediawiki::scap

* Rename mw-deployment-vars.sh to /etc/profile.d/mediawiki.sh
* Get rid of add-scap-to-path.sh; taken care of by mediawiki.sh above.
* Get rid of unused args.

Change-Id: Ibaa28d8cb93c440f909e075e767f47a30076b687
Merge "fold deployment::vars into mediawiki::scap" into production