Initial support for DBSubnetGroup
_sign_string private_key_file can now be file-like

Distribution._sign_string is now a little bit more flexible, allowing
the private_key_file to be a file-like object (or really anything with a
.read() method).
Added support for block device mappings in autoscaling groups (re #753, #1343)
updat incorrect copyright
Add missing function parameter (re: #1357)
add integration test
cloudformation Stack DisableRollback is always True

Fix problem where DisableRollback is always true, because
bool("False") == True
Adding updated values for recurring autoscale operations
Adding updated documentation for the new variables
Merge branch 'develop' of git://github.com/boto/boto into dbsubnetgroup
Fixed a bug where a ``date`` couldn't be set as metadata on a S3 key.
Merge branch 's3-metadata-date' into develop
Modify enumerate calls to not use the 'start' param as it is not supported in Python/Jython (2.5)
Added a failing test for ``nextToken`` in ``InstanceStatusSet``.
fix typo in xml parsing for InstanceStatusSet

The correct XML element name is 'nextToken', not 'NextToken'. (http://docs.aws.amazon.com/AWSEC2/latest/APIReference/ApiReference-query-DescribeInstanceStatus.html)
Merge branch 'ec2-instancestatus-nexttoken' into develop
Added a testcase to try to demonstrate #443.
Exposed the current tree hash & upload size on Glacier's ``Writer``.
Merge branch 'glacier-size-hash' into develop
Added ``Item.get(...)`` support to DDBv2.