Update EC2 to latest model

This switches from CLI specific filters to filters provided
in the operation documentation itself.
Merge branch 'ec2-update' into develop

* ec2-update:
  Update EC2 to latest model
Add event handler to quote the x-amz-copy-source header value as expected by S3.  Fixes https://github.com/aws/aws-cli/issues/614.
Merge pull request #221 from garnaat/fix-awscli-614

Add event handler to quote the x-amz-copy-source header value as expected by S3.
Support one level of nested configs

In the config file you can now say:

    [default]
    key = value
    nested =
        subkey = 1
        other = 2

And it will be parsed as:

    {'key': 'value', 'nested': {'subkey': 1, 'other': 2}}
Add handler to override signature version based on cfg value
Merge branch 'config-sigversion' into develop

* config-sigversion:
  Add handler to override signature version based on cfg value
  Support one level of nested configs
Backing out #221 for now.  It's causing errors in the integration tests.
Merge pull request #223 from garnaat/backout-221

Backing out #221 for now.  It's causing errors in the integration tests.
Update models to the lastet version
Bumping version to 0.32.0
Merge branch 'release-0.32.0' into develop

* release-0.32.0:
  Bumping version to 0.32.0
  Update models to the lastet version
Relicensed as Apache 2.0.
Merge branch 'apache-license' into develop
Fixes #224.
Never catch a bare except clause

While investigating aws/aws-cli#628 I noticed that I'd still
occasionally get tracebacks, particularly a DataNotFoundError
from botocore's base.py module.  After further investigation,
this was because the bare except clauses were catching the
KeyboardInterrupts and swallowing them.  This resulted in a
traceback somewhere downstream.

The specific error I hit from aws/aws-cli#628 was from base.py,
but I did a quick search through the code and for the time being
at least replaced the bare excepts with except Exception.  There's
potential to switch some of these to more specific exceptions later.
Merge branch 'no-bare-excepts' into develop

* no-bare-excepts:
  Never catch a bare except clause
Update route53 to the latest model
Bumping version to 0.33.0
Merge branch 'release-0.33.0' into develop

* release-0.33.0:
  Bumping version to 0.33.0
  Update route53 to the latest model
fix json -> xml request payload conversion

When creating request payload from json data, json `null` will now be converted to empty string '' not string 'None'.