Implement --terse option

Defined as suppressing logs of level INFO and below.

Altered from original '--quiet' patch with additional hacking from
Daniel Farina <daniel@heroku.com>.
Add Christophe Pettus as a contributor
Eliminate unecessary logging on restore

Tweak race error message by bumping severity to WARNING and note in the
message copy that the URI at one point existed but can no longer be
found.
Merge pull request #43 from bshi/wale-38

Eliminate unecessary logging on restore
Optimize out key.exists() call

Also try to retain the advantage that the error message returned when
a 404 is encountered still avoids the annoying gevent-instigated stack
trace.  This is done by converting exceptions into return values
rather than raising them to the top of the greenlet.
Untabify
Test compatability with newer boto

New Boto versions require a 'port' argument be supplied to
get_http_connection.
Change tox.ini style with multi-line settings

Prefer to indent to a consistent width (four spaces) and always
breaking the line after the '=' sign for multi-line settings.
Add pep8 and pyflakes checking and omission criteria

These settings are the ones used so far to vet WAL-E by me.  It seems
to add an inconsequential amount of run time to the test suite, and
will hopefully help contributors submit patches less laborious for
those who maintain this once-arcane and unwritten standard.
Add a development guide to the README

Mostly covers usage of tox and testing.
Updating project helpers for upcoming updates.
Reorganization of submodules to support additional data stores.

- Worker broken into two submodules, 'pg' (postgresql workers) and 's3'
  (s3 workers)
- New blobstore submodule added to help abstract away specifics of
  datastore interaction
Adding support for Windows Azure Blob Service as a datastore.
Merge pull request #47 from socrata/azure-support

Enabling easy addition of new data stores, adding Windows Azure Blob Service support
Add Brian Oldfield as a contributor.
Fix __all__ to use strings

Also alphabetize all the import and __all__ list lines, now that some
of the lists of exported functions are getting long enough to be
harder to scan.

Alex Gaynor <alex.gaynor@gmail.com> caught this systematic mistake of
mine in code review.
Fixes #50
All tablespaces are now backedup alongside base postgres data.
Moving away from TarFile.extractall in favor of per-member handling using TarFile.extract.
Merge pull request #51 from socrata/backup-all-tablespaces

Added optional flag to backup all tablespaces in addition to core postgr...