Support for lego's timeout option (#1041)

* Support for lego's timeout option

* Changed IntVar to DurationVar for catimeout

* Modified catimeout according to mholt's comments

caddy/caddymain/run.go

@@ -34,6 +34,7 @@ func init() {
 	flag.StringVar(&cpu, "cpu", "100%", "CPU cap")
 	flag.BoolVar(&plugins, "plugins", false, "List installed plugins")
 	flag.StringVar(&caddytls.DefaultEmail, "email", "", "Default ACME CA account email address")
+	flag.DurationVar(&acme.HTTPClient.Timeout, "catimeout", acme.HTTPClient.Timeout, "Default ACME CA HTTP timeout")
 	flag.StringVar(&logfile, "log", "", "Process log file")
 	flag.StringVar(&caddy.PidFile, "pidfile", "", "Path to write pid file")
 	flag.BoolVar(&caddy.Quiet, "quiet", false, "Quiet mode (no initialization output)")