MB-8030 Give explicit types for *all* numbers in couchstore.py

Change-Id: Ie41f09e20a2a6c83061c62fcdc69944c24565fb3
Reviewed-on: http://review.couchbase.org/26248
Reviewed-by: Bin Cui <bin.cui@gmail.com>
Tested-by: Aaron Miller <apage43@ninjawhale.com>