* include/am_defs.h : Merged a diff from 6.1 branch that addresses a

* include/am_defs.h : Merged a diff from 6.1 branch that addresses a
problem with GROUP_OBJ on Solaris 10:

Solaris 10 (build 72) defines GROUP_OBJ in <sys/acl.h>, which is included
in many other header files.  <rpcsvc/nis.h> uses GROUP_OBJ inside enum
zotypes.  So if you're unlucky enough to include both headers, you get a
compile error because the two symbols conflict.

* m4/macros/check_nfs_prot_headers.m4 : Fix to allow Solaris 10 to pick
up the right nfs header files.