Update Ansible to handle packages correctly

Correct installation of the libxslt-dev package requires a newer version of
Ansible - see http://github.com/ansible/ansible/issues/5177
Re-order tasks to start Solr correctly

The Solr Rake task requires database.yml to exist.
Stop Solr, to ensure starting is idempotent

An error occurs when we try to start Solr when it is running. So stop it
first to ensure build is idempotent.
Set biovel_portal_log variable

Variable was removed but is still used in vhost.j2