Ignore the -w flag for partial compataibility with FreeBSD.

Background:
	On FreeBSD, lookup failures for uname or gname generate fatal
	errors.  The -w flag converts those errors into warnings and
	does not print the [gu]name key.  The implementation is slightly
	wrong in that a directory containing a mix of files with a
	single resolvable username and files with unresolvable names
	gets an incorrect /set statment.

        On NetBSD name resolution failures result in [gu]id keys being
        printed.  This seems much better since it does not risk a change
        of ownership.

Index: mtree.8
===================================================================
--- mtree.8	(revision 240750)
+++ mtree.8	(revision 240751)
@@ -295,6 +295,9 @@
 Exit with a status of 0 on success,
 2 if the file hierarchy did not match the specification, and
 1 if any other error occurred.
+.It Fl w
+Ignored for compatibility with FreeBSD versions of
+.Nm .
 .It Fl W
 Don't attempt to set various file attributes such as the
 ownership, mode, flags, or time
Index: mtree.c
===================================================================
--- mtree.c	(revision 240750)
+++ mtree.c	(revision 240751)
@@ -77,7 +77,7 @@
 	init_excludes();
 
 	while ((ch = getopt(argc, argv,
-	    "cCdDeE:f:I:ik:K:lLmMnN:p:PqrR:s:StuUWxX:"))
+	    "cCdDeE:f:I:ik:K:lLmMnN:p:PqrR:s:StuUwWxX:"))
 	    != -1) {
 		switch((char)ch) {
 		case 'c':
@@ -177,6 +177,9 @@
 		case 'U':
 			Uflag = uflag = 1;
 			break;
+		case 'w':
+			/* Ignored for compatibility with FreeBSD's mtree. */
+			break;
 		case 'W':
 			mtree_Wflag = 1;
 			break;