Merge pull request #3 from schade/feature/Elastic_IP_enhanced

Feature/elastic ip enhanced
Merge pull request #4 from schade/feature/Elastic_IP_enhanced

Finalizing Enhanced Elastic IPs.
Miscellaneous fixes not related to any current issues
Fixed incorrect docstring describing use of allocation_id for VPCs
:auto_elastic_ip functionality to separate it from known :elastic_ip addresses; fixing docstrings for new features. Part deaux