#86 Specialize exception in ActiveInitator

[Jens Villadsen]

If a response is not received when sending a message over the ActiveInititor, a HL7Exception is thrown. However, at this point it would provide more value to throw something more specific, maybe a transport exception or a protocol exception or maybe something else. As I interpret the HL7Exception it is the most general form of exception for this framework, and not receiving a response for a request should deserve a more specialised exception.

[Christian Ohr]

Now throws a ca.uhn.hl7v2.app.TimeoutException (extends Hl7Exception)