SERVER-13337 support queries with projections in the idhack runner
SERVER-13686 import third_party/v8-3.25.28.14 JS2C Python scripts
SERVER-13686 V8 3.25 scripting engine. Disabled by default. Enable using SCons flag js-engine=v8-3.25
SERVER-13797 Remove usages of Client::getContext()

This change does not remove all usage of Client::getContext(), but only
the simpler ones.
SERVER-13641 Add warning to commit methods on Transaction
SERVER-13643 RIP BSONElementManipulator

If you really need to manipulate a BSONElement, do your own const_casting
SERVER-13643 Remove getDur() where we already have a TransactionExperiment
SERVER-13643 Use TransactionExperiment in dropDatabase()
SERVER-13643 Use TransactionExperiment in ExtentManager
SERVER-13643 Use TransactionExperiment in setHead()
SERVER-13617 remove const qualifiers on primitive return types

These tripped -Wignored-qualifiers on clang. With this change we now compile
cleanly on clang with -Wextra with only the following warnings disabled.
Neither seems worth fixing.

-Wno-unused-parameter
-Wno-missing-field-initializers
SERVER-13617 don't compare pointers to 0 using >

GCC with -Wextra gives the following message in these cases:

ordered comparison of pointer with integer zero
Merge remote-tracking branch 'upstream/master'