logs http.Server.Serve errors
adds http.Server equivalent API ListenAndServe, ListenAndServeTLS and Serve.
this allows the user to configured server details such as tls or timeouts
as well as handling errors from Listen and Serve without braking changes to Run.
Mention new api in readme
Merge branch 'newapi'
Merge pull request #14 from mb0/master

 graceful counterpart to http.Server methods