diag @warnings if the no-warnings test fails

( Also Correct .mailmap for kentnl )

```
21:34:33 < leont> ether: can't Test::Compile give a little more information on what warnings were observed?
21:36:09 < leont> I have no idea how to interpret this: 
                  http://www.cpantesters.org/cpan/report/5f4248bc-27bf-11e4-9612-bdb94915a708
21:36:09 < dipsy> [ CPAN Testers Reports: Report for App-s2p-1.002 ] 
21:47:55 < kentnl> +1 , looking at the source does indeed suggest it should || diag @warnings
21:50:40 < kentnl> leont: incidentally, you're getting it due to fail_on_warning = all
```