Add client mounting and associated magic.

* Rename gluster::client to gluster::mount
* Add support to gluster::mount
* Add client machines and mounts to vagrant setup
* Fixed version interface for gluster::mount and gluster::server
* Improved firewall support for gluster::mount
* Update examples to use gluster::mount instead of gluster::client
* Update documentation
* Other small fixes
Add support for setting the replica through vagrant.

This adds the --gluster-replica=N flag to the 'vagrant up' command.
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