SERVER-13951 Split index building in to UnitOfWork-sized stages

All index builds now go through the MultiIndexBuilder as its API was already
close to ideal. The following tickets have also been addressed by this commit:

SERVER-14710 Remove dropDups
SERVER-12309 Cloner build indexes in parallel
SERVER-14737 Initial sync uses bg index building
SERVER-9135 fast index build for initial sync
SERVER-2747 can't kill index in phase 2
SERVER-8917 check error code rather than assuming all errors are dups
SERVER-14820 compact enforces unique while claiming not to
SERVER-14746 IndexRebuilder should be foreground and fail fatally
SERVER-13951 WUOW now takes whole OperationContext, not just RecoveryUnit

This will make it possible to implement two-phase locking.
SERVER-8752 Fixed 'what' field value in Actionlog

Closes #744

Signed-off-by: Benety Goh <benety@mongodb.com>
SERVER-14729 assign default log component MONGO_LOG_DEFAULT_COMPONENT
SERVER-14827 Do not generate reports by default in errorcodes.py
SERVER-14756 The YAML storage.quota.enforced option is not found
SERVER-14904 Change dates in exportimport_date.js to account for different timezones in host environment

Closes #746

Signed-off-by: Benety Goh <benety@mongodb.com>
Revert "SERVER-14756 The YAML storage.quota.enforced option is not found"

This reverts commit 2c56cc550c8f3894e8631fd9862220352b255ab5
SERVER-14756 support storage.quota.enforced option in the YAML configuration

Closes #745

Signed-off-by: Benety Goh <benety@mongodb.com>
SERVER-14442 Ensure that we always send a repl handshake after reconnecting to our sync source
SERVER-14889 wrapped all malloc/realloc calls within src/mongo with mongoMalloc/mongoRealloc.
             if memory allocation fails, report error and exit.
SERVER-14128 Disallow requests for non-unique _id indexes
SERVER-13635: make capped8 a bit more generous as we push more data through now