[PATCH] fix xconfig for new help system

Here is a patch to enhance xconfig to read the new Config.help files.
Olaf Dietsche wrote this, and Steven Cole passed it on to me.

Testing: Steven Cole tested it, and I tested it.

scripts/header.tk

@@ -449,29 +449,24 @@ proc dohelp {w var parent}  {
 	catch {destroy $w}
 	toplevel $w -class Dialog
 
-	set filefound 0
 	set found 0
-	set lineno 0
-
-	if { [file readable Documentation/Configure.help] == 1} then {
-		set filefound 1
-		# First escape sed regexp special characters in var:
-		set var [exec echo "$var" | sed s/\[\]\[\/.^$*\]/\\\\&/g]
-		# Now pick out right help text:
-		set message [exec sed -n "
-			/^$var\[ 	\]*\$/,\${
-				/^$var\[ 	\]*\$/c\\
+
+	# First escape sed regexp special characters in var:
+	set var [exec echo "$var" | sed s/\[\]\[\/.^$*\]/\\\\&/g]
+	# Now pick out right help text:
+	set message [exec find . -name Config.help | xargs sed -n "
+		/^$var\[ 	\]*\$/,\${
+			/^$var\[ 	\]*\$/c\\
 ${var}:\\
 
-				/^#/b
-				/^\[^ 	\]/q
-				s/^  //
-				/<file:\\(\[^>\]*\\)>/s//\\1/g
-				p
-			}
-			" Documentation/Configure.help]
-		set found [expr [string length "$message"] > 0]
-	}
+			/^#/b
+			/^\[^ 	\]/q
+			s/^  //
+			/<file:\\(\[^>\]*\\)>/s//\\1/g
+			p
+		}
+		" /dev/null ]
+	set found [expr [string length "$message"] > 0]
 
 	frame $w.f1
 	pack $w.f1 -fill both -expand on
@@ -494,13 +489,8 @@ ${var}:\\
 	pack $w.f1.canvas -side right -fill y -expand on
 
 	if { $found == 0 } then {
-		if { $filefound == 0 } then {
-		message $w.f1.f.m -width 750 -aspect 300 -relief flat -text \
-			"No help available - unable to open file Documentation/Configure.help.  This file should have come with your kernel."
-		} else {
 		message $w.f1.f.m -width 400 -aspect 300 -relief flat -text \
 			"No help available for $var"
-		}
 		label $w.f1.bm -bitmap error
 		wm title $w "RTFM"
 	} else {