Add stats counter and improvement tests async and add Message-Authenticator support

[geaaru]

Some statistics enhancements for measure performance. On local machine with async server reach 600p/s requests without lost packets.

Can you bump a new release ?

Thanks in advance

[geaaru]

Wait, I missing some section of code with rebase of the master, i will update this soon.

[geaaru]

Sorry, I create wrong VerifyAuthPacket on previous pr and I fix documentation for every verify methods (it was inverted). I tested it with freeradius and it seems works fine.

I'm not sure that current async server support correctly Status-Server feature, I will try to test and integrate eventually some fix in the next weeks.

[GIC-de]

Please rebase from master to solve the conflicts!!!

[geaaru]

Can you merge pr now or do you think that is needed some more changes ? I will try to integrate support to Status-Server message in a separated pr.

[geaaru]

Please, check my code with Message-Authenticator support and fix for CHAP authentication.

It seems that

chr(chapid).encode('utf-8')

doesn't work correctly when int > 128. I see this with radclient test.

I think that it's ready to merge. Let me know. Thanks