configuring / modifying request timeouts

[Matthew Hall]

Hello,

I am working on some code which needs to attempt to resolve a gigantic list of 
domains, many of which are going to be unresolveable. When troubleshooting and 
optimizing this I am finding that the adns code has a hard-coded amount of UDP 
retries and retry time.

#define UDPMAXRETRIES 15
#define UDPRETRYMS 2000

After changing to 5 retries it can still cost 20 seconds, which is confusing 
because I would have expected 10 seconds. Also, a whole ton of unit tests 
start to fail if you reduce it.

So I'm just trying to understand how to get it to work the best in these kinds 
of scenarios.

Thanks,
Matthew.