Consistently call name on formula instead of relying on to_s
mariadb: remove dead code

The "client-only" option was removed on account of it not working.
juju: simplify install
erlang: remove warning

It doesn't take *that* long on modern hardware, and we have other
packages that take longer.
audit: access the homepage attribute once
Added qt-assistant-compat package.
qt-assistant-compat: add 4.6.3 bottle.