mongo-wire: Drop GByteArray.
mongo-wire: Drop GByteArray.

GByteArray was a terrible overkill for what mongo-wire was doing, so
replaced it with a raw bytestream.

Suggested by Balazs Scheidler <bazsi@balabit.hu>.

algernon/libmongo-client,algernon/libmongo-client,algernon/libmongo-client