ccampbell/mousetrap — pull request #50 by loris (2012-08-03 15:08:36+00:00)
Title: Added extend method

New method that allows the user to add custom keyboard codes.
For instance, to make use of PC Media keys in mouse trap :

```
Mousetrap.extend({
173: 'mute',
174: 'volumedown',
175: 'volumeup',
176: 'nexttrack',
177: 'previoustrack',
178: 'stop',
179: 'playpause'
});
```