Adds initial ErrorCodes file

Author: dresende

lib/ErrorCodes.js

@@ -0,0 +1,21 @@
+exports.QUERY_ERROR      = 1;
+exports.NOT_FOUND        = 2;
+exports.NO_SUPPORT       = 3;
+exports.MISSING_CALLBACK = 4;
+exports.PARAM_MISSMATCH  = 5;
+
+Object.defineProperty(exports, "generateError", {
+	value: function (code, message, extra) {
+		var err = new Error(message);
+		err.code = code;
+
+		if (extra) {
+			for (var k in extra) {
+				err[k] = extra[k];
+			}
+		}
+
+		return err;
+	},
+	enumerable : false
+});