Implemented default values for the App Engine limit and number_found_accuracy parameters in the search API that should improve both count accuracy and API performance.  Also set the default namespace and index name in the testing environment to work with local test data generated by dwc-indexer.
Updated the default production namespace to use the latest index.
Merge pull request #436 from VertNet/feature/apifixes

Set App Engine parameter defaults to improve count accuracy and performance for the search API.