Replace .SA Obsolete by .LV Obsolete

Mark obsolete pages with '+' in subject pages.  Drop the separate
"Obsolete" subject page: move "info Innards" to subject "Server", and
"info update" to "Updates" (where it came from in commit a5764534,
v4.3.10).

info/Innards.t

@@ -1,6 +1,6 @@
 .TH Concept Innards
 .NA Innards "Some details about the inner workings of the server"
-.LV Expert
+.LV Obsolete
 .s1
 Much of this file is now out-of-date.  Correct information may be found
 in the files Update-sequence and build.
@@ -243,4 +243,4 @@ dependent on the efficiency and the work force in the capital sector.
 (see info BTU).
 .s1
 .s1
-.SA "Education, Happiness, Products, Research, Technology, Time, BTU, Obsolete"
+.SA "Education, Happiness, Products, Research, Technology, Time, BTU, Server"

info/README

@@ -49,7 +49,7 @@ The second line must be a name header:
 
 The third line must be a level header:
 .LV arg
-  - arg must be a level, one of Basic, Expert
+  - arg must be a level, one of Basic, Expert, Obsolete
 
 The last line should be a see also:
 .SA "item1, item2, ..., subject1, subject2"

info/mksubj.pl

@@ -44,6 +44,8 @@ use File::stat;
 # The chapters, in order
 my @Chapters = qw/Introduction Concept Command Server/;
 
+my @Levels = qw/Basic Expert Obsolete/;
+
 my $filename;
 my (%subject, %level, %desc, %long, %cnt);
 my $largest = "";
@@ -78,6 +80,7 @@ for my $chap (@Chapters) {
     for (split(/\n/, $subject{$chap})) {
 	my $flags = "";
 	$flags .= "*" if $level{$_} eq 'Basic';
+	$flags .= "+" if $level{$_} eq 'Obsolete';
 	$flags .= "!" if $long{$_};
 	$flags = sprintf("%-2s", $flags);
 	print SUBJ ".L \"$_ $flags\"\n";
@@ -95,6 +98,9 @@ print SUBJ <<EOF if $cnt{'Basic'};
 Subjects marked by * are the most important and should be read by new
 players.
 EOF
+print SUBJ <<EOF if $cnt{'Obsolete'};
+Subjects marked by + are obsolete.
+EOF
 print SUBJ <<EOF if $cnt{'long'};
 Unusually long subjects are marked with a !.
 EOF
@@ -140,8 +146,8 @@ sub parse_file {
 
     $_ = <F>;
     if (/^\.LV (\S+)$/) {
-	if ($1 ne 'Basic' && $1 ne 'Expert' && $1 ne 'Obsolete') {
-	    error("The argument to .LV was '$1' but it must be either 'Basic', 'Expert', or 'Obsolete'");
+	if (!grep(/^$1$/, @Levels)) {
+	    error("The argument to .LV was '$1', which is not a known level");
 	}
 	$lvl = $1;
     } else {

info/update.t

@@ -1,8 +1,8 @@
 .TH Command UPDATE
 .NA update "Find out when the next update will be"
-.LV Basic
+.LV Obsolete
 .SY "update"
 The update command shows you when the next update will occur, and
 describes the current update policies.
 .sp
-.SA "show, zdone, Obsolete"
+.SA "show, zdone, Updates"