idiag: merge branch 'idiag-fixes'

Deprecate all of the IDIAG_* defines in 'idiagnl.h'.
Names exposed by libnl should have the prefix IDIAGNL_*
instead.

But actually, most of these values were copies from other
system headers. The user should instead use the original defines
anyway.

Also, several fixes of the idiag_msg_obj, which had a broken
oo_clone() function and missing oo_compare().

http://lists.infradead.org/pipermail/libnl/2014-November/001726.html

Signed-off-by: Thomas Haller <thaller@redhat.com>