chore(logging): add logging via Winston and wrapped it with a custom logging module

src/logging.js

@@ -0,0 +1,34 @@
+var nconf = require('nconf');
+var winston = require('winston');
+
+var logger;
+if (logger == null) {
+    // We currently don't support logging on Heroku
+    if (nconf.get('NODE_ENV') != 'production') {
+        logger = new (winston.Logger)({
+            transports: [
+                new (winston.transports.Console)({colorize: true}),
+                new (winston.transports.File)({ filename: 'habitrpg.log' })
+                // TODO: Add email, loggly, or mongodb transports
+            ]
+        });
+    }
+}
+
+// A custom log function that wraps Winston. Makes it easy to instrument code
+// and still possible to replace Winston in the future.
+module.exports.log = function(/* variable args */) {
+    logger.log.apply(logger, arguments);
+};
+
+module.exports.info = function(/* variable args */) {
+   logger.info.apply(logger, arguments);
+};
+
+module.exports.warn = function(/* variable args */) {
+    logger.warn.apply(logger, arguments);
+};
+
+module.exports.error = function(/* variable args */) {
+    winston.error(arguments);
+};