Adding missing health_check value for weighted record sets.
Add test case check for setting healthcheck property on resource record.
Add "attributes" parameter to boto.dynamodb2.table.Table.batch_get
Add support for SNS message attributes.

See http://docs.aws.amazon.com/sns/latest/dg/SNSMessageAttributes.html

Fixes boto#2339
SNS message attributes fixes after actually testing with AWS.

Also make tests pass under python 2.6.
Remove redundant lines in auth.py
Fix SWF continue_as_new_workflow_execution start_to_close_timeout.
add unit test for dynamodb2 Table.batch_get (based on test_private_batch_get)
Get rid of an explicit setting AF_INET to socket as

IPv6 is coming. So give a chance to establish connection via IPv6.
emr module: add backward-compatible support for Python 3.3+
elastictranscoder module: add backward-compatible support for Python 3.3+
elb module: add backward-compatible support for Python 3.3+
Merge pull request #2381 from felixonmars/emr-py3

emr module: add backward-compatible support for Python 3.3+. Fixes #2381.
Merge pull request #2382 from felixonmars/elastictranscoder-py3

elastictranscoder module: add backward-compatible support for Python 3.3+. Fixes #2382.
Fix StringIO imports and invocations. Fixes #2386
Merge pull request #2387 from phspagiari/develop

Fixed wrong call of urlparse. Fixes #2387.
Merge pull request #2384 from felixonmars/elb-py3

elb module: add backward-compatible support for Python 3.3+. Fixes #2384.
Merge pull request #2390 from danielgtaylor/fix-stringio

Fix StringIO imports and invocations. Fixes #2390.
Merge pull request #2276 from appneta/add_ddb2_batch_get_attributes

Add "attributes" argument to boto.dynamodb2.table.Table.batch_get. Fixes #2276.
Merge pull request #2378 from severb/develop

Fix SWF continue_as_new_workflow_execution start_to_close_timeout. Fixes #2378.