Clustering datastore tests for Lithium.

Clustering datastore tests for Lithium.

Some datastore functionality has changed between Helium and Lithium. The crud and settings libraries
needed to be modified for changes in restconf for the cars shard. Also, an unneccessary sleep was removed
from the crud library. Because there's a difference in the installed features required for Hydrogen
and Lithium cluster testing, the multi-node-test clustering template was changed. Some other features to
help with troubleshooting were also added. Finally, the clustering template temp directory was added to
gitignore to simplify test development.

Change-Id: I8b704d57af64985d8d4be6d2454601371c0f55e8
Signed-off-by: Phillip Shea <phillip.shea@hp.com>