MB-7542 Fix unset revision number on deserialization

Change-Id: I18b1f478c3fed736e381ea1eb970d811b318d37d
Reviewed-on: http://review.couchbase.org/24000
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
MB-6895 Better map function error isolation

If an error occurs for a map function of a view group,
don't discard the results from all other map functions
of the view group.

Change-Id: I49dde86e6698b018dade35d7ca7257f12ba53b86
Reviewed-on: http://review.couchbase.org/24205
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
MB-7413 Periodically call file:advise/4

After a full batch is read from the temporary file, tell
the OS that the data read from the file won't be accessed
anymore, so that it can remove it from its page cache.

Change-Id: Ia5645df48bcfd563abbd9ca75fe0248e039659dc
Reviewed-on: http://review.couchbase.org/24229
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: Filipe David Borba Manana <fdmanana@gmail.com>
Merge remote-tracking branch 'origin/2.0.1'

Conflicts:
	src/mapreduce/test/01-map.t

Change-Id: I1c8f67f97d1c6f0db05094745a67d715dae3a215