added ctor in JsonObject taking IEqualityComparer<string> (#23)
added ctor in JsonObject taking IEqualityComparer<string> (#23)

ndevenish/simple-json,jasonmead/simple-json,jasonmead/simple-json,facebook-csharp-sdk/simple-json,suaff/simple-json,facebook-csharp-sdk/simple-json,ndevenish/simple-json,ndevenish/simple-json,suaff/simple-json,jasonmead/simple-json,suaff/simple-json,facebook-csharp-sdk/simple-json