Add a new method on SwaggerSpecConfig which allows the end user to specify an arbitrary delegate which is used to determine whether or not an endpoint should be included in the index.  Includes a new test for this feature.
inverted the behavior of the delegate.  changed method name to be more consistent.  changed delegate to be a private member rather than a property.
Merge pull request #130 from vertiman/master

Added a configuration delegate to ignore some endpoints in the index