Add product install task

The product task makes easy to install every product distribution. If
needed it can create a virtual machine by specifying create_vm argument
is True. Also it can setup a DDNS entry if required environment
variables are set.

Rename install tasks to match the pattern <distribution>_install and use
better know distribution names.

Add aliases to ensure backward compatibility.
Add setup_vm_provisioning task

The task will setup all required packages and a network bridge device in
order to allow the target machine manage virtual machines using vm tasks.
Merge pull request #65 from elyezer/product-install-task

Add product install task
Merge pull request #66 from elyezer/provisioning-infra

Add setup_vm_provisioning task
Updated tasks to use ``systemctl`` for RHEL 7.

Updated tasks to use ``systemctl`` instead of ``service`` to manage
services as well as use OS-version specific service names (e.g.
``firewalld`` versus ``iptables``).

String formatting uses indexes to accommodate older versions of Python.

Also, cleaned up the ``cdn_install`` task by removing its ``subscribe``
and ``install_prerequisites`` calls since these already already handled
by ``product_install``.
Merge pull request #68 from omaciel/rhel-7

Updated tasks to use ``systemctl`` for RHEL 7.