WaspError should include info about Exceptions coming from Volley

[kardeslik]

For example, when TimeoutError occurs we could not know the exception is due to time out because all we get from Wasp is a WaspError with status code 0 and null message.

[shiva4411]

Same problem with UnknownHostException. Please handle error codes

[orhanobut]

Let's have this one as top priority, I am also having some issues with this.

[cutiko]

If you are reading this you might find this explanation for error 0 interesting #139