JsonHelper testing, and use of Newtonsoft.Json library to compile/decompile JSON

When I tried to parse a WSSE security header with **JsonHelper**, I noticed that the **DataContractJsonSerializer** doesn't return the wanted output.

That is because, the WSSE patterns has extra commas and colons in the value string, like that:

```
UsernameToken Username="foo@bar.net", PasswordDigest="ZTQXXXXXXXXXXXXXXXXXXXXXXXXXXXX0NTJlMGE2M2I0NGJiYWM4NA==", Nonce="XXXXXXXXXXXXXXXXXXXXXXXXXXXXA==", Created="2014-10-11T18:48:07.232Z"
```

I recommend to delegate the serialization/deserialization of JSON in the library Newtonsoft.Json for performance and a better result.