librados: drop #include of int_types.h from installed headers

These are unnecessary, and breaks compilation for outside users.

Prefer inttypes.h over stdint.h.

Signed-off-by: Sage Weil <sage@inktank.com>
Merge pull request #685 from ceph/wip-rados-ints

librados: drop #include of int_types.h from installed headers

Reviewed-by: Dan Mick <dan.mick@inktank.com>