Add tests for file sorter callback and skip_writeback option
Add tests for file sorter callback and skip_writeback option

Change-Id: I87246cf28fdb3b524d219d7f92c82ffb425c4326
Reviewed-on: http://review.couchbase.org/32660
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Filipe David Borba Manana <e0fcd583df77ec6c08e6d1257619cc1216ddc994@gmail.com>
Tested-by: Filipe David Borba Manana <e0fcd583df77ec6c08e6d1257619cc1216ddc994@gmail.com>

vmx/couchstore,couchbaselabs/couchstore,vmx/couchstore,vmx/couchstore,couchbaselabs/couchstore,jimwwalker/couchstore,couchbaselabs/couchstore,abhinavdangeti/couchstore,jimwwalker/couchstore,abhinavdangeti/couchstore,jimwwalker/couchstore,abhinavdangeti/couchstore