[getdns-api] call_debugging extension

[John Dickinson]

I have implemented the call_debugging extension. It raised a couple of 
issues with the API:

1. Added a tls_auth_status field to tell you if the server was 
authenticated
2. Added a transport field to tell you what transport was actually used
3. removed start_time and end_time as these are defined as uint64_t’s 
but the dict can only handle 32 bit ints.
4. Added run_time field to contain  end_time - start_time as a uint32_t

entire_reply and dnssec_result have not yet been implemented.

regards
John