Output geocouch into the common build directory

Change-Id: Ic1cc924386e4bf807dce8b83b33f9fb0ac7ae28b
Reviewed-on: http://review.couchbase.org/41774
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>