feat(onUpdate): accept a callback as options.onUpdate

If options.onUpdate is provided, it will be called with the stats
results of the compilation on every build.

In combination with setting options.quiet, it allows the user to
manually handle the logging of the stats.

Author: Merott

README.md

@@ -47,6 +47,10 @@ app.use(webpackMiddleware(webpack({
 	// switch into lazy mode
 	// that means no watching, but recompilation on every request
 
+	onUpdate: function(stats) { doWhateverWithStats(stats); },
+	// manually handle the stats from the last compilation
+	// can be combined with quiet and noInfo for full control over output
+
 	watchOptions: {
 		aggregateTimeout: 300,
 		poll: true

middleware.js

@@ -40,6 +40,10 @@ module.exports = function(compiler, options) {
 		process.nextTick(function() {
 			// check if still in valid state
 			if(!state) return;
+
+            // make a callback with stats
+			if(typeof options.onUpdate === 'function') options.onUpdate(stats);
+
 			// print webpack output
 			var displayStats = (!options.quiet && options.stats !== false);
 			if(displayStats &&