Initial commit of botocore client waiters

This allows for waiters to accept either the
Service/Operation interfaces or the client interfaces.
Update README to add note about back-compat

Also add some very basic upgrading notes for the early adopters.
Add utility class to generate input arguments

This class generates a sample input structure
based on an input shape.  It also handles recursive
shapes.

I've added both unit tests and integration tests.
The integration tests are more "end to end" in the sense
that they load actual AWS service models and verify that
for every non empty input shape, we're able to generate
sample skeletons.
Update emr integ tests
Merge branch 'waiter-shared' into develop

* waiter-shared:
  Update emr integ tests
  Initial commit of botocore client waiters
Add docstrings to the ArgumentGenerator class
Merge branch 'generate-skeletons' into develop

* generate-skeletons:
  Add docstrings to the ArgumentGenerator class
  Add utility class to generate input arguments
Merge branch 'more-docs' into develop

* more-docs:
  Update README to add note about back-compat
Don't parse response body when output shape is None

Fixes #352.  To ensure no other protocols were susceptible,
I reorganized part of the response parsing unit tests such that
testing for output shapes of None are grouped in a single class.

I've also added an integration test to ensure this functionality
with an actual AWS service.  This helps ensure we don't regress
in the future.
Update cloudsearchdomain to the latest version

Fixes aws/aws-cli#943
Merge branch 'no-output-shape' into develop

* no-output-shape:
  Don't parse response body when output shape is None
Remove v1 models

These were kept around for parity checks, but they are no
longer needed now.

Also I've updated the docs to remove anything about model translations.
Merge branch 'remove-v1-models' into develop

* remove-v1-models:
  Remove v1 models
Fix failing tests

When switching to sigv4, the region _is_ required.
These tests are updated appropriately, one to not use a sigv4
service, the other, to verify we raise an NoRegionError because
we didn't provide an error.
Merge branch 'update-cloudsearchdomain' into develop

* update-cloudsearchdomain:
  Fix failing tests
  Update cloudsearchdomain to the latest version
Fix flattened map parsing of a single element

Closes #345

This affects the parsed of th `aws sqs get-queue-attributes` command.
Merge branch 'fix-map-parsing' into develop

Closes #345.

* fix-map-parsing:
  Fix flattened map parsing of a single element
Updated JSON models

This includes rds, kinesis, cloudsearch, and elastictranscoder.
Bumping version to 0.66.0
Merge branch 'release-0.66.0' into develop

* release-0.66.0:
  Bumping version to 0.66.0
  Updated JSON models