Expose more options when initializing Google v3 Layer

[ianmcodes]

Currently there are very few Google specific options exposed when initializing the Google maps v3 layer. That means that implementing the kind of styles that you can see on a site like http://snazzymaps.com/, requires first initializing the Google layer then directly modifying the options on the map object.

Example:

var styles = []; // some styles for Google Maps.
var glayer = new OpenLayers.Layer.Google.v3("google",{ "type": google.maps.MapTypeId.ROADMAP, "maxZoomLevel": 18});
glayer.mapObject.setOptions({ "styles": styles });

It would be great to be able to set this in the options (along with other options that Google exposes).

One question would be how to expose the Google options without conflicting with OpenLayers options. A couple possible solutions to that would be to preface all of the Google options with "google-" or to have a "googleOptions" option that would be an object of options for Google.