Add option to provide configuration file on command line

cmd/web.go

@@ -55,6 +55,7 @@ and it takes care of all the other things for you`,
 	Action: runWeb,
 	Flags: []cli.Flag{
 		cli.StringFlag{"port, p", "3000", "Temporary port number to prevent conflict", ""},
+		cli.StringFlag{"config, c", "custom/conf/app.ini", "Configuration file", ""},
 	},
 }
 
@@ -165,6 +166,9 @@ func newMacaron() *macaron.Macaron {
 }
 
 func runWeb(ctx *cli.Context) {
+	if ctx.IsSet("config") {
+		setting.CustomConf = ctx.String("config")
+	}
 	routers.GlobalInit()
 	checkVersion()