Replaced url/mime pairs with ERNResource class
Renamed ERNUrlMimeFactory to ERNResourceFactory
Changed URLResource functions mime/urlForObject to resourceForObject
Renamed ERNNullUrlMimeFactory To ERNNullResourceFactory
Renamed ERNNumberMimeUrlFactory to ERNNumberResourceFactory
Renamed ERNRoutingUrlMimeFactory to ERNRoutingResourceFactory
Renamed ERNStringUrlMimeFactory to ERNStringResourceFactory
Renamed ERNURLUrlMimeFactory to ERNURLResourceFactory
Renamed ERNDefaultUrlMimeFactory to ERNDefaultResourceFactory
Renamed test cases from url/mime to resource
Renamed final url/mime parts to resource