SERVER-13961 AuthzSessionExternalStateMongod::startRequest doesn't need a lock check

When called from DBDirectClient, it already skips the check if running
under isGod context.
SERVER-13961 Remove some usages of Lock::isLockedXXX and dbtemprelease

These are the most obvious usages, which do not require any refactoring.
SERVER-14173 Patch Boost to unbreak the build on VS 2013
Merge remote-tracking branch 'upstream/master'