include config header
fix len values
ignore ^C
implement toxdns3 username lookups
Add configure checks for libresolv
Remove redundant toxav header check

If pkg-config reports that toxav is there, it should be enough, no extra
checks needed.
Merge pull request #142 from jin-eld/add-libresolv

Add libresolv
..
don't need this
threads for DNS lookups
exit dns threads with pthread_exit
merge