The idea of a common handle is long revised and only misleading,
nl_handle really represents a socket with some additional
action handlers assigned to it.
Alias for nl_handle is kept for backwards compatibility.
I stepped over libnl always freeing the messages and it
kind of made it awkward to reuse the message data without
reallocating.
The basic idea is: if a callback return value has a bit set,
don't free that message. The calling application owns it.
By default, things stay as before (messages are freed).
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
