add AsyncResult && coroutines module
change luaL_error -> luaL_argerror
cooperative dns client
add test dns
modify readme
dns resolver support ipv6: comform to rfc1886
modify default dns server
add queue
add semaphore
add simple http proxy
change flush_two_socket to efficient way.

Two coroutine will be created to copy data from point to point.
add select
add method_CONNECT support
Merge pull request #4 from spin6lock/http_proxy

Http proxy
Add port forward tool. This tool will direct 8080 port content to 80
Changed to two coroutine to flush
add signal module
Merge pull request #5 from spin6lock/portforward

Portforward