Cluster configuration script should copy initial configuration files.

Cluster configuration script should copy initial configuration files.

The current version of configure_cluster.sh script needs the odl-mdsal-clustering
feature to be pre-configured, so that the configuration/initial/ directory has
the necessary cluster config files.

This fix will copy the initial configuration files, if they do not exist
currently. Also, I fixed two other issues:
 - The script failed to run if it was executed in the bin directory.
 - Some lines had tabs instead of spaces.

Change-Id: Iee27a37ef681831bd4c3f8496694c52bdc1613e0
Signed-off-by: Shaleen Saxena <ssaxena@brocade.com>
(cherry picked from commit 7086ff0638858d40e99055af3a16d64ea81010a5)