Add support for Amazon VPC APIs
Updated all VPC code to move from roboto to requestbuilder backend.
Updated CLI output to match Amazon CLI output.
Updated diff based on gholms comments
Add describe security groups
Move BUFSIZE to a higher module
Clean up S3 GetObject
Fix GetObject integrity checks
Update download-bundle for new GetObject code
Major cleanup/refactor of download/unbundle code
Fix euare call-chaining weirdness
Some PEP8 cleanup (requires newer requestbuilder)
Move commands.euca -> commands.ec2
Rename EucalyptusRequest -> EC2Request
Move commands.walrus -> commands.s3
Rename WalrusRequest -> S3Request
Move commands.euare -> commands.iam
Rename EuareRequest -> IAMRequest
Use strptime instead of dateutil.parse

Fixes TOOLS-449
Don't use choices= for Filters

Globs are legal characters in filters, so stop using choices= in Filter
objects so people can use them.

Fixes TOOLS-426