add swift storage alternatives for storage library

- add support for OpenStack Swift based storage (non-rackspace)
- add register_swift_protocol decorator to facilitate adding Swift endpoints.
  - requires a scheme (e.g. "hpcloud") and auth_endpoint when wrapping
    a CloudFilesStorage subclass.
  - exports decorator at toplevel along with get_storage()
- add HPCloudStorage endpoint to support HP Helion cloud storage
  - storage uri's have the format:
      "hpcloud://user:pass@container/obj?region=REGION&tenant_id=ID"
- includes unit tests for changes
added documentation for 'swift' and 'hpcloud' schemes.
minor doc updates
minor doc update
update based on review feedback.

- made CloudFilesStorage a subclass of SwiftStorage
- created a generic register_storage_protocol() decorator that
registers new storage protocols with the storage library.
- updated register_swift_protocol() decorator for adding Swift
based storage classes.
- updated README
- minor changes
- updated unit tests
minor README update
update README with decorator documentation.

- doc for register_storage_protocol
- doc for register_swift_protocol
added register_storage_protocol unit test

- made register_storage_protocol available at top-level
- include unit test for register_storage_protocol
updates to README.md from review comments.
updated pyrax version and storage lib version #.

- update to use pyrax 1.9.2 which has the chunk_size fix
- update storage library version number
Merge pull request #11 from ustudio/storage-swift-alt

add Swift support

- supports other OpenStack Swift implementations other than Rackspace (e.g. HP Helion)