added deprecation warnings for contentBase

Author: stutrek

lib/Server.js

@@ -130,23 +130,31 @@ function Server(compiler, options) {
 		var contentBase = options.contentBase || process.cwd();
 
 		if(typeof contentBase === "object") {
+			console.log('Using contentBase as a proxy is deprecated and will be removed in the next major version. Please use the proxy option instead.\n\nTo update remove the contentBase option from webpack.config.js and add this:');
+			console.log('proxy: {\n\t"*": [your current contentBase configuration]\n}');
 			// Proxy every request to contentBase.target
 			app.all("*", function(req, res) {
 				proxy.web(req, res, contentBase, function(err) {
 					var msg = "cannot proxy to " + contentBase.target + " (" + err.message + ")";
 					this.io.sockets.emit("proxy-error", [msg]);
 				}.bind(this));
 			}.bind(this));
+
 		} else if(/^(https?:)?\/\//.test(contentBase)) {
+			console.log('Using contentBase as a proxy is deprecated and will be removed in the next major version. Please use the proxy option instead.\n\nTo update remove the contentBase option from webpack.config.js and add this:');
+			console.log('proxy: {\n\t"*": "'+contentBase+'"\n}');
 			// Redirect every request to contentBase
 			app.get("*", function(req, res) {
 				res.writeHead(302, {
 					'Location': contentBase + req.path + (req._parsedUrl.search || "")
 				});
 				res.end();
 			}.bind(this));
+
 		} else if(typeof contentBase === "number") {
 			// Redirect every request to the port contentBase
+			console.log('Using contentBase as a proxy is deprecated and will be removed in the next major version. Please use the proxy option instead.\n\nTo update remove the contentBase option from webpack.config.js and add this:');
+			console.log('proxy: {\n\t"*": "http://localhost:'+contentBase+'"\n}');
 			app.get("*", function(req, res) {
 				res.writeHead(302, {
 					'Location': "//localhost:" + contentBase + req.path + (req._parsedUrl.search || "")