How to Create a Google Maps Shortcode

To demonstrate how easy it is to build custom shortcodes, we'll build one to display a Google Map based on a provided address. We want our CMS authors to be able to embed the map using the following code:

	[googlemap,width=500,height=300]97-99 Courtenay Place, Wellington, New Zealand[/googlemap]

We'll add defaults to those in our shortcode parser so they're optional.