Configuration file needs to belong to prosody user

Don't copy the LE certificates.  Instead use the ssl-cert group to
manage access to the LE certificates directly.  See
https://github.com/letsencrypt/letsencrypt/issues/1425 for a request to
have the LE client do this itself.

resolves #453

Conflicts:
	roles/common/tasks/ufw.yml

resolves #453

This is the updated version from the prosody repository because
these distributions have an old version of the lua-sec package
that lacks PFS and other features. Second commit for issue #285.

* Postfix: Trusty comes with postgresql 9.3, not 9.1
* owncloud 6.0.1 is part of the distribution, doesn't require opensuse repository
* owncloud requires libapache2-mod-php5
* uses prosody repository that matches the ansible_distribution_release (trusty, wheezy, etc)

String-valued variables containing spaces can be substituted into an ansible
tasks file but they will not be interpreted correctly.