JCLOUDS-401. Make BlobName Function type-safe
Fixing rackspace-clouddatabases-{us,uk} openstack-trove dependency groupIds
Switch to maven-compiler-plugin 3.1
JCLOUDS-410. Correctly override getInput

Payload.getInput must always call openStream to handle overridden
methods correctly.  Previously this caused errors in jclouds-chef in
BaseCipherPayload.