Merge branch 'release-1.5.0' into develop

* release-1.5.0:
  Bumping version to 1.5.0
  Update CHANGELOG with new entries
Add botocore issue to changelog
Fix error message for unknown keys

We now include the correct CLI argument name in the
error message, before we were using the xformed py_name,
which would give use things like --foo_bar instead of --foo-bar.

Error messages for unknown keys now looks like:

```
Error parsing parameter '--policy-attributes': Unknown key 'name', valid choices are: AttributeName, AttributeValue
```
Fix bug for py3 in shorthand error message
Add bug fix to the changelog
Merge branch 'shorthand-unknown-key' into develop

* shorthand-unknown-key:
  Add bug fix to the changelog
  Fix bug for py3 in shorthand error message
  Fix error message for unknown keys
Handle recursive shapes in shorthand parser
Document recursive shapes

For now we just document one level of recursion and then
note that it's recursive.  I've added some basic unit tests
that at least verify the doc generation process doesn't get stuck
in an infinite loop.
Expand '~' in credentials filename

Otherwise we try to write a file '~/.aws/credentials'
which is not what we want.  Originally reported on the
AWS CLI forums.
Add configure bugfix to the changelog
Add dynamodb feature to the changelog
Bumping version to 1.5.1
Merge branch 'release-1.5.1'

* release-1.5.1:
  Bumping version to 1.5.1
  Add dynamodb feature to the changelog
  Add configure bugfix to the changelog
  Expand '~' in credentials filename
  Document recursive shapes
  Handle recursive shapes in shorthand parser
  Add bug fix to the changelog
  Fix bug for py3 in shorthand error message
  Fix error message for unknown keys
  Add botocore issue to changelog