common-ha: handle long node names and node names with '-' and '.' in them

common-ha: handle long node names and node names with '-' and '.' in them

sourcing the /etc/ganesha/ganesha-ha.conf file seemed like a simple
and elegant solution for reading config params, but bash variable names
do not allow '-' and '.' in them.

Also fix incorrect path in shared volume mount

Change-Id: I40140e5da0903221efd316de94dce40229263e15
BUG: 1225572
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>
Reviewed-on: http://review.gluster.org/11035
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>