isDayLightSavingsTime() doesn't exist

```

The documentation for getTimezoneAbbreviation() shows
Date.today().isDayLightSavingsTime() in the example, but this method is
nowhere to be found in the source.

Link to documentation which shows this:
http://code.google.com/p/datejs/wiki/APIDocumentation#getTimezoneAbbreviation

This would be a tremendously useful function to have! I'll see if I can
implement it like to implement this and contribute it back (although this
looks project is dead, so I'm not sure how well the latter will go).
```

Original issue reported on code.google.com by `Mr.Adam....@gmail.com` on 30 Mar 2010 at 6:36