run_instance tweaks: Cannot submit subnet with group name; must use group id instead. Added support for this edge condition.  Also added PrivateIpAddress option.
Add support BlockDeviceMapping into create_image method
Merge pull request #18 from brettpaden/options_for_run_instance

run_instance tweaks
Added optional parameter AddressingType (deprecated but still implemented in EC2 API and usefull for eucalyptus clouds with only private addressing)
Merge pull request #20 from vincent-k/master

Added optional parameter 'AddressingType' to the 'runInstance' method.
Add support for IAM instance profiles in run_instances
Merge pull request #24 from jimbrowne/iam-profile

Add support for IAM instance profiles in run_instances
Merge pull request #19 from hirose31/feature/create_image-blockdevicemapping

Add support BlockDeviceMapping into create_image method