CXX-281 Merge upstream changes for SERVER-5668

SERVER-14482 Add add missing appendX methods to BSONArrayBuilder

Conflicts:
	src/mongo/bson/bsonobjbuilder.h
	src/mongo/bson/mutable/document.cpp
	src/mongo/dbtests/jsobjtests.cpp
CXX-275 Backport server r2.7.2..r2.7.3 changes