Look over the install rules and adjust where appropriate

These are just minor tweaks to make sure the 'make install' part does
what it is supposed to do.  I also removed some commented code in the
dtmail Makefile related to SunOS, as that is not currently suppoerted
anyway.

cde/programs/dtsession/Makefile.am

@@ -131,10 +131,10 @@ sys.session.ive: sys.session.src
 # systems without a PAM library need dtsession to be SUID root
 
 install-exec-hook:
-	chown root $(DESTDIR)$(bindir)/dtsession
 if HAS_PAM_LIBRARY
 	chmod 755 $(DESTDIR)$(bindir)/dtsession
 else
+	chown root $(DESTDIR)$(bindir)/dtsession
 	chmod 4755 $(DESTDIR)$(bindir)/dtsession
 endif