apache: get rid of apache::vhost

* Get rid of apache::vhost and its template. It is no longer in use.
* Get rid of LICENSE since there is literally not a single line left from the
  PuppetLabs module.

Change-Id: Iabec0a4d4e8b12ff7f4a6f2cde177e9166f88548
apache: improve docs; provision apache::def before apache::{mod_conf,conf}

Change-Id: I25ed305caf1fd2576531a9d283602de483699b2f