Fix ListMultipartUploads operation in s3 model to include CommonPrefixes and Prefix elements in output.  Add tests for normal response and response with CommonPrefixes.  Modify test generator slightly to allow multiple XML response files for a given operation.  Fixes #85.
Fixing space/tab issue.
Removing CDATA sections and other unparsable content from doc strings for dynamodb and sns.  Working on tools to filter these out when building models but these are done manually just to get working models back into the repo.