Merge remote-tracking branch 'refs/remotes/upstream/v2.6' into convey-2.6
post 2.6.0-rc2
SERVER-13306 mongobridge should not try forever to connect to dead
destinations.

The connect timeout is set to 15 seconds of retrying, after which the
connection to the client will be terminated.

Also added some extra logging and diagnostics so it is easier to analyse
test failures in the future.
Apply fix to bench_test3.js to jsCore version
(cherry picked from commit 9d359723b373e6ca31bbd353f5d3add44777c9a3)
SERVER-13307 do not try to index ELEM_MATCH_VALUE if a child predicate can't be indexed

(cherry picked from commit 9713848c54f3a0a25f9682d21a35179e6b8a3a86)
SERVER-13331 lower GridFS default chunk size to 255k

(cherry picked from commit 632ae4e7ad70426d5e2d36bd1fee4491eeac16b7)
SERVER-13328 enhance "updater not supported" error message

(cherry picked from commit 84ae6f501a9eb27d19c8c4f668fa806220421f7d)
SERVER-13334 fix maxTimeMS shell helper with count
(cherry picked from commit 5138b611cbb384f87c0437d51f1fe3a72a4bf7b4)
SERVER-13336 count should always yield

Revert "SERVER-12554 Lazily yield on count queries."

This reverts commit 2850cc7253344c639bc9a01bc6dff3ffd2cca422.
SERVER-13342 add a createCollection() to guard against timeouts in tags.js

(cherry picked from commit b8c7f25613fee7c6bf77dda941589fe367c14385)
remove jstest/multiClient because it has only one test in it which isn't run and wouldn't do anything anyway

jstest/libs/concurrent.js is also being removed because this was the only thing that used it

(cherry picked from commit ce5a47a3b506cbd0154c60144deb5cd0e6a3aea9)
SERVER-13297: convert parallel suite to use jsCore tests

(cherry picked from commit 835a7cc8ea3c564d34876d20b90b37750d7e30c5)
SERVER-13266 log messages with typos

Signed-off-by: Matt Kangas <matt.kangas@mongodb.com>
(cherry picked from commit d238d44ac27a50604279b3c61077b88b5582103a)
SERVER-13347 Clear execStats in OpDebug::reset()

(cherry picked from commit 23adfff477e84ef38d342da5767e77a139bcacfe)
Merge remote-tracking branch 'refs/remotes/upstream/v2.6' into convey-2.6
Merge remote-tracking branch 'refs/remotes/origin/convey-2.6' into convey-build
SERVER-13332 fix scary messaging around unsharded cursors
(cherry picked from commit e0867ea625ccca214dd6fbf079001a6b097c0ef2)
SERVER-13297: remove dead jstests

(cherry picked from commit 57f97f213346b7a0305c81fd70894a77ca35a886)
SERVER-13312 Fix type of operationProfiling.mode
(cherry picked from commit 997eedb2565ac005a7c489d9234813de8b27bc2f)
SERVER-13310 Check error status for nested configuration data
(cherry picked from commit 67fcecca64281afcefce51c61a1f08699145fc56)