Fixes to ec2 lib
Fixes to ec2 lib

Make name argument optional on more methods (may be a pre-
populated parameter)

Fix calls to resolve_instance to assign both return values

When terminating, only remove dns if the state was 'running',
otherwise there will be no DNS

uva-its/ruby-awstools,uva-its/ruby-awstools,uva-its/ruby-awstools