Merge branch 'glacier' of github.com:boto/boto into glacier

Conflicts:
	boto/glacier/layer2.py
Fixed tests
Added glacier to the readme :)
Merge remote-tracking branch 'almost/glacier' into glacier
Pep8 cleanup to glacer l2 unit tests

Also switched the assert statements to use
assertEqual for better error diagnostics.
Remove leading whitespace in glacier modules
Reduce memory usage for chunk_hashes

On a 180MB file this reduced total memory
usage by approximately 40%.  This was also marginally
faster (but not by much).

I've also added the start of unittests for the writer module,
and I've written some very basic unittests for the chunk_hashes
function.
Allow single op threshold to be configurable

This is the threshold at which the Vault class will
use a multipart upload instead of a single operation
upload.
implement snapshot.create_volume()
Put docs for parameters in the same order as parameters
Allow non-numerics in a Constraint attributes. Fixes issue #941.
Allow non-numerics in a RegExConstraint's attributes. Fixes issue #941.
Get_batch return empty answer for empty batches
add integration test for empty batch
add connect_glacier to the main boto object.
Moved setmeta logic from GSUtil to boto.
Fixed style errors; added metadata normalization to boto.key.
Added retreive-inventory function
Allow upload_archive to accept file like objects

The entire file is never read into memory, only (configurable)
single chunks are read at a single time.
Merge pull request #968 from jamesls/glacier-perf

Reduce memory usage for chunk_hashes