Values missing in at%H response shouldn't cause problems now.

Intead of expecting a certain order of the response values we take what we get. Missing values depending on different setups are OK.
Removed unused command and renamed command parser to fit it's function
Added satus changed event for SerialNetDevice, subscribe and know when it changes status!

Need to implement actual status changes though and a thread that manages the device so we can keep track of connection loss etc.