Added experimental _spatial/bbox for the GeoCouch extension.

I emitted a dummy geometry rather than the actual GeoJSON to minimize the size
of each row. 'coordinats: ""' works, and it is smaller than 'coordinates:
"undefined"', to which the plugin would default if none are given.
Changed map page to check for the GeoCouch extension.

Don't know what to do with the spatial info right now, so I ignored it.
WIP:

- geocouch
- removed parseInt because they look stupid