Figure out what to do about locations

[gaul]

jclouds abstracts the physical placement of data in Location which can be configured via the jclouds.region and jclouds.regions properties. This is poorly documented in the S3Proxy and it isn't obvious how to create a new bucket when using the Azure backend. Ideally this should work out of box and us-east1 should map to whatever the provider's default location is. Other user-specified locations should map to the underlying storage backend location.