Remove no longer used checkpoint logic

This is not longer useful as of MB-7413. After each large batch
is applied a checkpoint is always performed.

Change-Id: I203c6192b9e2a763c9844b868e8de16d5781922f
Reviewed-on: http://review.couchbase.org/25011
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
Simplify max seq numbers calculation

Merging 2 lists of sequence numbers (by maximum) is
already performed by the function process_map_results/3.

Change-Id: I1728dc55ce2a34d3c148bbaa7f6f73e89a69d328
Reviewed-on: http://review.couchbase.org/25012
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
More precise compaction time calculation

When measuring the duration of view compaction, account for
the initial step of coordinating with the updater if the
updater is running in parallel. Normally this is very fast,
but for some edge cases it can take a significant amount of
time, as it did in MB-7280 (Windows environment).

Change-Id: I666c0d418c6eeda14fee92a89dc2b599b1b48355
Reviewed-on: http://review.couchbase.org/24255
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-on: http://review.couchbase.org/25013
Reviewed-by: Volker Mische <volker.mische@gmail.com>
MB-7873 Ensure blocked indexer tasks die if updater dies

If the updater process dies (shutdown by view group for e.g.),
ensure the corresponding blocked indexer active task will die
as well. This is ensured by keeping both processes linked all
the time.

Change-Id: If326a001c3baa106ea0f2dd46717b881e794fd3b
Reviewed-on: http://review.couchbase.org/25018
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
MB-7882 No id btree lookups for dynamically added partitions

If a partition is dynamically added to the updater while
it's running, add it to the list of new partitions, so
that id btree lookups aren't performed for documents
comming from that partition - just like what is done for
new partitions that were added before the updater started.

This only has impact under high memory pressure scenarios,
because the same btree nodes will end up being visited
later by the pipeline stage which updates the btree.

This should have been included as part of the MB-7522,
commit ac82c60302422747e8804d566211a20684ec78fb:

"Optimize index state transitions (rebalance)"

Change-Id: If47f821445d0fa5e98ec74d89ea79d1b0a91c45e
Reviewed-on: http://review.couchbase.org/25050
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Tested-by: Filipe David Borba Manana <fdmanana@gmail.com>
Merge remote-tracking branch 'origin/2.0.2'

* origin/2.0.2:
  MB-7882 No id btree lookups for dynamically added partitions
  MB-7873 Ensure blocked indexer tasks die if updater dies
  More precise compaction time calculation
  Simplify max seq numbers calculation
  Remove no longer used checkpoint logic

Change-Id: I16956c85c3f1aff39210660cc65ec11ca0817bb3