SERVER-14062 StorageEngine::cleanShutdown should not accept OpCtx

There should not be active OperationContext when cleanShutdown is called,
because it should be run under a global lock and should not be acquiring
locks or performing recoverable operations.

This change is necessary for the removal of the OperationContext registry
and ensuring there is one OperationContext per client.
SERVER-16410 suppress missing-braces warning on clang
SERVER-15875 rename new_find.{h,cpp} to find.{h,cpp}

Also renames newRunQuery and newGetMore to runQuery and getMore.
SERVER-16407: Fix lock_mgr_test memory leak for ASAN build
SERVER-16400 Correct bounds in replica set config validation error message
SERVER-16160 memberID->memberId
SERVER-16375 Prevent truncating of log message about remote node vetoing us
SERVER-16161 Log failed heartbeat requests at default verbosity
SERVER-14062 Remove the global OperationContext registry
BUMP 2.8.0-rc2
Merge remote-tracking branch 'upstream/master'