tor: additional optional deps

An additional optional dep for Tor.

Also removes the example file, as upstream regenerate it periodically
and currently we don’t seem to respect that regeneration and leave
outdated sample files in etc.

Adds a set of caveats about the ` torrc ` file, similar to the ones we
have for ` clamav ` and others.
tor: update 0.2.5.10 bottle.