Put request handler on SimpleServer.prototype (#2627)

The request handler may be used by ExpressJS apps directly and can do most of the heavy lifting without any modification. Note that the self variable must be assignee using `[Function].bind(null,SimpleServer instance)`.

core/modules/commands/server.js

@@ -91,10 +91,9 @@ SimpleServer.prototype.checkCredentials = function(request,incomingUsername,inco
 	}
 };
 
-SimpleServer.prototype.listen = function(port,host) {
-	var self = this;
-	http.createServer(function(request,response) {
+SimpleServer.prototype.requestHandler = function(request,response) {
 	// Compose the state object
+	var self = this;
 	var state = {};
 	state.wiki = self.wiki;
 	state.server = self;
@@ -141,7 +140,10 @@ SimpleServer.prototype.listen = function(port,host) {
 			});
 			break;
 	}
-	}).listen(port,host);
+};
+	
+SimpleServer.prototype.listen = function(port,host) {
+	http.createServer(this.requestHandler.bind(this)).listen(port,host);
 };
 
 var Command = function(params,commander,callback) {