console: Add common aliases for console methods

- add common aliases as per following spec
- https://github.com/DeveloperToolsWG/console-object/blob/master/api.md

Author: aks-

lib/console.js

@@ -40,6 +40,9 @@ Console.prototype.log = function() {
 Console.prototype.info = Console.prototype.log;
 
 
+Console.prototype.debug = Console.prototype.log;
+
+
 Console.prototype.warn = function() {
   this._stderr.write(util.format.apply(this, arguments) + '\n');
 };
@@ -48,6 +51,9 @@ Console.prototype.warn = function() {
 Console.prototype.error = Console.prototype.warn;
 
 
+Console.prototype.exception = Console.prototype.warn;
+
+
 Console.prototype.dir = function(object, options) {
   this._stdout.write(util.inspect(object, util._extend({
     customInspect: false