Defaulting BackupInfo.spec to dict for backwards compatibility. Fixes #53
Update README.rst

fixed grammar
Merge pull request #54 from sneak/patch-1

Update README.rst
Add Jeffrey Paul as a contributor
Remove superflous out-of-date comment

The decision since that time that unification of configuration
for each backend will not be attempted.
Disable bucket name validation in s3_worker

This can cause problems when one is using IAM policies that
restrict actions to a prefix in the bucket.

Also avoids one API call in the common case where the bucket is valid,
although later calls that touch the bucket for the first time must be
ready for an invalid bucket to raise exceptions.
Alphabetize imports
Rework credential configuration management

Credentials are now opaque objects except to the specific blob store
implementation that uses them.  This is to allow worker function
signatures to retain the same signature between backend storage
implementations even though different backends have different methods
of authentication that go beyond the account name/password approach.

While doing this, teach the S3 credential regime a 'security token'
parameter, which allows use of keys vended by AWS STS.
Add tests stressing AWS STS credentials and functionality
Remove dead parameter for .delete_all
Fix thinko: creds has no prefix attribute, layout does
Drawing distinction between prefix and path_prefix.

- ``layout.prefix`` refers to the full URL prefix for a resource.
- ``layout.path_prefix`` refers specifically to the path portion of the
  prefix.
- Moving to ``os.path.join`` in place of straight string interpolation
  in the few places interpolation was used for URL construction.
Fixed call to wabs.uri_get_file
Fixed signature of blobstore.wabs.CallingInfo.connect.
Merge pull request #57 from socrata/fixup_55

Fixing up a few bugs introduced in last refactor.
Fixing WABS uploads for large files. Fixes #56
Merge pull request #58 from socrata/fix-wabs-upload-size

Fixing WABS uploads for large files. Fixes #56
Make sure symlinks to tablespaces do not make it into tar partitions.
Adding retry logic around WABS chunk upload and download.
Eliminating use of os.path.join for URL construction.