Support node startup with the JNLP Launcher

Original author is James E. Blair in the devstack-gate project.

Change-Id: I92d363e5916adfd07744b959080f8b6c3b660ceb
Merge "Support node startup with the JNLP Launcher"
Support node configuration

Bring support for node configuration with  get_node_config() and
reconfig_node().  This comes from OpenStack Nodepool project originally
written by James E. Blair in the devstack-gate project.

Closes-Bug: #1234273
Change-Id: I29423d8bab5fd74f1c7f63002d1be7a2ae0be176