Vanilla minor fixes

This pull request includes the following fixes:

- Merged hotfix 0.95.6 from trunk starcluster into branch to fix problem creating instances with recent versions of boto
- a bug fix for an exception which occurs when "starcluster terminate --force" is run and the master node is offline (but the security group still exists)
- a bug fix for a failure in the load balancer which manifests when the cluster exceeds 100 nodes