aws/aws-cli — pull request #935 by jamesls (2014-10-07 21:08:13+00:00)
Title: 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
```

cc @danielgtaylor @kyleknap