Fix up FreeBSD tag for files not from a vendor branch

Unexpand the tag, remove the fbsd:nokeywords property and add the
svn:keywords property.  This should eliminate the gratuituous diffs
that appear on these files in projects branches.

Sponsored by:	The FreeBSD Foundation

lib/libz/FREEBSD-upgrade

@@ -1,4 +1,4 @@
-$FreeBSD: head/lib/libz/FREEBSD-upgrade 146082 2005-05-11 03:50:50Z kientzle $
+$FreeBSD$
 
 ZLib 1.2.2
 

lib/libz/Makefile

@@ -1,5 +1,5 @@
 #
-# $FreeBSD: head/lib/libz/Makefile 232263 2012-02-28 18:30:18Z dim $
+# $FreeBSD$
 #
 
 LIB=		z

lib/libz/Symbol.map

@@ -1,5 +1,5 @@
 /*
- * $FreeBSD: head/lib/libz/Symbol.map 206709 2010-04-16 20:07:24Z delphij $
+ * $FreeBSD$
  */
 
 ZLIB_1.2.7.1 {

lib/libz/Versions.def

@@ -1,4 +1,4 @@
-# $FreeBSD: head/lib/libz/Versions.def 205486 2010-03-22 22:12:27Z delphij $
+# $FreeBSD$
 
 ZLIB_1.2.4.0 {
 };

lib/libz/zopen.c

@@ -3,7 +3,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/libz/zopen.c 84228 2001-09-30 22:39:00Z dillon $");
+__FBSDID("$FreeBSD$");
 
 #include <stdio.h>
 #include <zlib.h>