Make cleanup work with spatial views

The cleanup of the mapreduce views is performed in the native C
based cleaner and updater. The spatial views still use some
Erlang code path to cleanup the views.

This commit makes it the spatial views possible to do a proper
cleanup.

Change-Id: I431fecbcecb1276271c9ed5930e4bf304c5ef412
Reviewed-on: http://review.couchbase.org/40116
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Sarath Lakshman <sarath@couchbase.com>