Add MinAdjustmentType for autoscaling.

When policy_type is PercentChangeInCapacity, allows values of
min_adjustment_type, which set the AWS MinAdjustmentType value for
autoscaling policies.
Add mobile push API
Add unit tests for publish operation
Add target_arn to publish method in SNS client
PEP8 fixes for EC2 MinAdjustmentStep
Merge branch 'release-2.9.9' into develop

* release-2.9.9:
  Bumping version to 2.9.9
Added notes about merging pull requests.
Add unit tests for EC2 auto scaling policy MinAdjustmentStep
Added a failing test for set changes in DDBv2.
Altering how state tracking of ``Item`` data works in DDBv2.
update cacerts from mozilla.org

Used mk-ca-bundle.pl locally to generate a recent cacerts.txt file that
fixes https certificate validation for OSX 10.8x. These certs were built
with:

$ perl mk-ca-bundle.pl -w 64 boto/cacerts/cacerts.txt

fixes boto/boto#1535
closes jtriley/StarCluster#267
Added a failing test for CloudSearch's Layer2.
fix for https://github.com/boto/boto/issues/1629
Only include MinAdjustmentStep as a parameter if it has been set in order to prevent changing existing behavior; updated unit tests to show this behavior.
-w flag never actually checked s3 for a file's existence. Always refused to upload.
added non-zero exit statuses for unsuccessful runs

Previously, the program always exited 0 unless it crashed.  This covered many of the failure scenarios like "permission denied" and "The specified bucket does not exist", but didn't cover anything that would provoke usage() to be called ("-h" notwithstanding)

This adds an arbitrarily ascending list of non-zero exit codes to all the cases of "usage" and also the exit() called for unaviliable multi-part upload.  usage() not defaults to exit status 1, since -h has been covered and most other uses of usage() would be for error conditions
Merge remote-tracking branch 'taylordt/ec2-min-adjustment-type' into develop
Fixed the sending of empty data to DDB as well.
add DynamoDB ap-southeast-2 endpoint
Merge branch 'jtriley-update-cacerts' into develop

Closes # 1578.

* jtriley-update-cacerts:
  update cacerts from mozilla.org