Add definitions for the osversionmin, osversionmax, and osversionin

attributes.  We don't use these yet, but they've been hanging around my
tree for ages, and it's time other people got to play with them.

Add (HTML) entity defs for lsquo and rsquo, ` and ' respectively.

share/sgml/freebsd.dtd

@@ -7,7 +7,7 @@
 
      The FPI for this DTD is "-//FreeBSD//DTD DocBook V3.1-Based Extension//EN"
 
-     $FreeBSD$
+     $FreeBSD: doc/share/sgml/freebsd.dtd,v 1.3 1999/09/06 06:53:40 peter Exp $
 -->
 
 <!-- ..................................................................... -->
@@ -30,6 +30,17 @@
 <!-- Character level classes -->
 <!ENTITY % local.tech.char.class "|HostID|Username|Devicename|MakeTarget|MakeVar">
 
+<!-- OS Version attributes ...............................................
+
+     Each element has three attributes which specify which version(s) of
+     FreeBSD the element's content applies to.  It is up to the
+     pre-processor to include or exclude elements based on the value of
+     these attributes.                                                     -->
+<!ENTITY % local.common.attrib
+     "OSVersionMin        CDATA        #IMPLIED
+      OSVersionMax        CDATA        #IMPLIED
+      OSVersionIn         CDATA        #IMPLIED">
+
 <!-- Altered general entities ............................................
 
      The HTML 4.0 DTD includes some new ISO entities. Most browsers don't
@@ -44,8 +55,10 @@
 <![ %output.html; [
 <!ENTITY ldquo  "``">
 <!ENTITY rdquo  "''">
-<!ENTITY mdash  "---">
-<!ENTITY ndash  "--">
+<!ENTITY lsquo  "`">
+<!ENTITY rsquo  "'">
+<!ENTITY mdash  "--">
+<!ENTITY ndash  "-">
 <!ENTITY hellip "...">
 <!ENTITY dollar "$">
 ]]>