BSON: Smooth out memory handling of data buffers
Update Mongo and tests for BSON API changes
Update gridfile_get_metadata to take advantage of BSON subobject copying
Merge remote-tracking branch 'origin/master' into bson_ownsData

Conflicts:
	src/bson.c
	src/mongo.c
	test/write_concern_test.c
Merge pull request #93 from noa--/bson_ownsData

BSON: Smooth out memory handling of data buffers