Using wrong variable to replace tenant.

The shift configuration was wrong because the user name was set as tenant.
Naive mirroring implementation
keys and secrets
use setuptools
Added config entry for source_index
Merge pull request #224 from chilicat/patch-1

Openstack glance/swift - Using wrong variable to replace tenant.
app: Don't require Bugsnag if we don't use it

With this commit, we delay any bugsnag-related import errors until we
actually need the bugsnag module (which may be never, depending on the
user's config).
Merge pull request #241 from wking/optional-bugsnag

app: Don't require Bugsnag if we don't use it
Fix log message

Properly uses the name of the method where the entry is emitted.
Merge pull request #243 from davidhoyt/patch-1

Fix log message
README.md: Add config/ prefix to config_sample.yml

This catches the docks up with 900d262 (Moved config to the config/
directory, 2013-12-09).
Reworked source_lookup, storing json/ancestry/etc locally, removed decorator (obsolete)
Merge pull request #240 from wking/readme-config-location

README.md: Add config/ prefix to config_sample.yml
tags: Factor get_tags out of the _get_tags endpoint

Gettings a nicely-parsed list of tags is useful internally, so pull
the tag-listing logic out into it's own function.  The decorated
endpoint behind GET /v1/repositories/<path:repository>/tags is *not*
useful internally, so prefix that function with an underscore.

To convert the get_tags iterator to a dictionary, I've used a dict
comprehension [1], which landed in Python 2.7 and 3.0.  I couldn't
find any docs on docker-registry's minimal supported Python version,
so I imagine compatibility with ancient Pythons is not high on the
agenda.

[1]: http://www.python.org/dev/peps/pep-0274/
tags: Factor delete_tag out of the _delete_tag endpoint

Deleting a tag (and raising the associated signal) is useful
internally, so pull the tag-deleting logic out into it's own function.
The decorated endpoint behind
DELETE /v1/repositories/<path:repository>/tags/<tag> is *not* useful
internally, so prefix that function with an underscore.
Merge pull request #233 from mmerickel/feature.setuptools

use setuptools
Tags are mutable, they shouldn't be stored on mirrors
Added tags caching support (with TTL)
Fix test_layers tests. Tentative fix for #248
Merge pull request #249 from dotcloud/fix-tests

Fix test_layers tests. Tentative fix for #248