create a JSTL custom tag to pretty print Date objects using prettytime

Dear prettytime team,

I would like to contribute to your library with a custom JSTL tag that pretty prints Date objects with prettytime.

A sample usage is to include the following snippet in a JSP page:

```
<ocpsoft:prettytime date="${myDate}" locale="en_US"/>
```

This will render HTML output with prettytime result.

Best regards,
Benas