Add support for secure (Kerberized) NFSv4
Update README.md to include reference to nfs_v4_secure parameter
Manage the rpcgssd service on redhat
Use Shellvars lens instead of Sysconfig lens for /etc/sysconfig/nfs

See the following bug report - the Sysconfig lens is less reliable,
and the default for /etc/sysconfig is the Shellvars lens

    https://bugzilla.redhat.com/show_bug.cgi?id=1043636
Merge branch 'nfs4_secure' of git://github.com/jonathanunderwood/puppet-module-nfs into jonathanunderwood-nfs4_secure
Added  $nfs_v4_secure = false paramter to some files.
Merge branch 'jonathanunderwood-nfs4_secure' into v.2.0.x

Conflicts:
	manifests/client.pp
	manifests/client/debian.pp
	manifests/client/redhat.pp
	manifests/server/redhat/service.pp