bugzid 3437: fixed assign and delete private ip
bugzid 3400: return helpful error messages when launching server with no subnet
Merge pull request #38 from daniellemayne/2013.07

2013.07 - bugzids 3437 and 3400
[maven-release-plugin] prepare release dasein-cloud-openstack-2013.07.4
[maven-release-plugin] prepare for next development iteration
Merge branch '2013.07'
Updating pom version