Rename of swift hook file

- Rename python module from swifthook.py to openstackswifthook.py
- Rename class from OpenstackSwiftHook to OpenStackSwiftHook
- Update the hooks in config.py
--- Provide example for when using OpenStack Swift
--- Make default sane
Storage URL from Service Catalog

- Rename swifthook.py to openstackswifthook.py and correct capitizalization of OpenstackSwiftHook
- Update the OpenStack Swift Hook to parse the service catalog encoded as a base64 json string in the x-service-catalog header field for the local datacenter's storage url and update the deuce context
- Update config.py to include a setting for the datacenter (region)
- Update the test_functional.py to use self.assertEqual instead of assert so we can see the values on both sides of the equation in failures
Test Cleanup

- Convert more tests over to using self.assert*
- Re-enabled the OpenStack Hook and OpenStack Swift Hook in config.py so it can be covered in the testing
- Bug Fix; Missed line with class name change of the OpenStackSwiftHook class
- Further consolidated where the openstack portion of the deuce context is configured for the tests
- Reduced use of specifying headers and initializing the Deuce Context to a minimal, it's now entirely done in the setUp functions
Test Hooks

- Disabled the OpenStackHook and OpenStackSwiftHook in default configuration
- Add a test specific to testing the OpenStackHook
- Add a test specific to testing the OpenStackSwiftHook
- Refactored OpenStackSwiftHook to be able to mock it up
- Disabled X-Auth-Token check in test_functional as it is not relevant unless the OpenStackHook is enabled
Test Cleanup

Removed the x-auth-token portion of the test it's in another, hook specific test
Style/Compliance

- pep8 compliance
Merge branch 'master' into enhancement_hook_storage_url
Documentation

- Denoting which section to use when
Cleanup

- Rename default DC to something more generic
- Remove X-Auth-Token headers from all tests that do not need it
Cleanup

- Do not import hooks we don't need unless we need to
Docstring it

- Moved the OpenStackObject used to create the Deuce Context structure to the global namespace in deuce.hooks.openstackhook and added a docstring on it
- Imported the OpenStackObject from OpenStackHook into OpenStackSwiftHook; no need to create it twice and no reason it cannot depend on the other hook (it kind of already does implicitly)
Merge branch 'master' into enhancement_hook_storage_url

Conflicts:
	deuce/tests/test_sqlite_storage_driver.py
Remove init_context

- Turns out nothing uses init_context() so why keep it around?
feat: delete block endpoint

Blocks can now be deleted, if they have no references. A status
code of 204 is then returned.
A Constraint Error is raised by the metadata driver if there
are references, and 412 is returned as status code.

Endpoint:
    DELETE /v1.0/vaults/{vault}/blocks/{blockid}
fix: delete from storage as well as metadata

Delete from storage, and if it succeeds delete from
metadata.
Change disk storage driver to return False if the block
didnt exist and return 404 if it ain't present.
fix: Constraint Error

per Xuan's comments
Add "Constraint Error" keyword in exception msg
Merge remote-tracking branch 'upstream/master' into block_deletion_endpoint
add: x-file-length header on finalization of file
rm: unused imports
add: exception handling on metadata - block delete