[RELEASED] six 1.6.0

I'm releasing six 1.6.0. It has a few more backports and another attempt to solve the great lazy proxy module problem suggested by Diana Clark. Here's the changelog: - Raise an AttributeError for every attribute of unimportable modules. - Issue #56: Make the fake modules six.moves puts into sys.modules appear not to have a __path__ unless they are loaded. - Pull request #28: Add support for SplitResult. - Issue #55: Add move mapping for xmlrpc.server. - Pull request #29: Add move for urllib.parse.splitquery.