Proposal to enhance Rados Java: list of Objects by piece

1) Mainly: add listing by piece for listObjects() since many objects could not fit in memory (List)

2) Also change to public the close method of Rados (why it was protected?)

Request: could it be possible to have Xattr method accessible from Java too?
Also, is there any way to get the number of objects in a pool ?

The performances are great until now.