Adding secondary nodes to lbaas

* Split load_balancer_nodes into 2 tables, child_load_balancers
  and load_balancer_nodes. child_load_balancers how hold info
  common to all nodes of a load balancer.
* Generate and return a vip UUID. This is the UUID used to identify
  the LB in subsequent http calls.
* Added a PUT function to add the secondary node to a given LB.
First cut of sentinel monitoring

* Created a method to do slave promotion and master demotion.
* Added true/false flip of primary_node in the nodes table.
Adding sentinel configuration

* Fixed the primary node flip to wait if the node is PENDING.
* Cleaned up the sentinel monitor / sentinel code.
* Created a binscript for the monitor.
Getting packages ready

* checkin in node_modules and fixing up the Makefile