somewhat fixup a bson related error
somewhat fixup a bson related error

The bson stuff requires a bit more testing though so to make sure to
properly report when people are using the wrong bson library as we
depend on a few specific features of the mongodb one.

cuckoobox/cuckoo,cuckoobox/cuckoo,cuckoobox/cuckoo,cuckoobox/cuckoo,cuckoobox/cuckoo