MB-19897: Record time for all DCP consumer messages

MB-19897: Record time for all DCP consumer messages

The DCP documentation states that the consumer should see
some sort of message or a No-Op message in a period
equal to twice the noop interval otherwise it should close
its connection.  See documentation/commands/no-op.md in
https://github.com/couchbaselabs/dcp-documentation

This patch changes from checking only the receival of a
no-op message to check for recieving the following messages
- add stream
- close stream
- deletion
- expiration
- flush
- mutation
- set VBucket state
- snapshot Marker
- stream end

Change-Id: Ib2268dba339cbf3701f3c7782ee8256bddc79ba3
Reviewed-on: http://review.couchbase.org/64879
Tested-by: buildbot <build@couchbase.com>
Well-Formed: buildbot <build@couchbase.com>
Reviewed-by: Dave Rigby <daver@couchbase.com>