support for more flags in the placefinder query

I needed to do a reverse geocode query, which required setting gflags=R when making the query.

placefinder() can still be called with just a query string, but calling with an array gets you access to all the query args:

```php
			$yplace = $this->placefinder( array(
				'location' => $coords[0] . ',' . $coords[1],
				'gflags' => 'R',
			) );
```
initial unit test scaffold

See http://maisonbisson.com/post/17645/unit-testing-wordpress-plugins/