Add test that we don't allow invalid datatypes

Clients trying to send an illegal datatype will be disconnected

Change-Id: Icb6b3193b053619823b8dd99424b5cf1b1bb5985
Reviewed-on: http://review.couchbase.org/35451
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>