Several Load Balancer enhancements

This implements several enhancements to load balancers. These were started and thoroughly tested in another fork of wakame-vdc.

# Additions

* LB monitoring
* Manually set mac address, ip address and host node for LB
* Use 2 security groups for LB. One for firewall rules and one for registered instances
* fix load balancer active stanby update error.
* Delete LB in database if its instance terminates abnormally
* Includes this pull request: https://github.com/axsh/wakame-vdc/pull/188