Adding Geo bbox query

What do you think about using the `vertices` syntax for defining the bbox?

I personally always get confused about the ordering of the elements in these arrays, the `vertices` syntax allows you to specify `top,left,bottom,right` individually, which might help prevent errors.

Have you given much thought to how the latlon pairs will be defined in the rest API `GET` params? Maybe we could use the same for both to make it clearer.