[PATCH] Improve look-and-feel of the gitk tool.

Made the default buttons on the dialog active and focused upon the
dialog appearence.

Bound 'Escape' and 'Return' keys to the dialog dismissal where it
was appropriate: mainly for dialogs with only one button and no
editable fields.

Unified the look of the "About gitk" and "Key bindings" dialogs.

Signed-off-by: Eygene Ryabinkin <rea-git@codelabs.ru>
Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -938,12 +938,15 @@ Gitk - a commit viewer for git
 Copyright © 2005-2006 Paul Mackerras
 
 Use and redistribute under the terms of the GNU General Public License} \
-	    -justify center -aspect 400
-    pack $w.m -side top -fill x -padx 20 -pady 20
+	    -justify center -aspect 400 -border 2 -bg white -relief groove
+    pack $w.m -side top -fill x -padx 2 -pady 2
     $w.m configure -font $uifont
-    button $w.ok -text Close -command "destroy $w"
+    button $w.ok -text Close -command "destroy $w" -default active
     pack $w.ok -side bottom
     $w.ok configure -font $uifont
+    bind $w <Visibility> "focus $w.ok"
+    bind $w <Key-Escape> "destroy $w"
+    bind $w <Key-Return> "destroy $w"
 }
 
 proc keys {} {
@@ -994,12 +997,15 @@ f		Scroll diff view to next file
 <Ctrl-minus>	Decrease font size
 <F5>		Update
 } \
-	    -justify left -bg white -border 2 -relief sunken
-    pack $w.m -side top -fill both
+	    -justify left -bg white -border 2 -relief groove
+    pack $w.m -side top -fill both -padx 2 -pady 2
     $w.m configure -font $uifont
-    button $w.ok -text Close -command "destroy $w"
+    button $w.ok -text Close -command "destroy $w" -default active
     pack $w.ok -side bottom
     $w.ok configure -font $uifont
+    bind $w <Visibility> "focus $w.ok"
+    bind $w <Key-Escape> "destroy $w"
+    bind $w <Key-Return> "destroy $w"
 }
 
 # Procedures for manipulating the file list window at the
@@ -5892,14 +5898,15 @@ proc doprefs {} {
     grid x $top.hunksepbut $top.hunksep -sticky w
 
     frame $top.buts
-    button $top.buts.ok -text "OK" -command prefsok
+    button $top.buts.ok -text "OK" -command prefsok -default active
     $top.buts.ok configure -font $uifont
-    button $top.buts.can -text "Cancel" -command prefscan
+    button $top.buts.can -text "Cancel" -command prefscan -default normal
     $top.buts.can configure -font $uifont
     grid $top.buts.ok $top.buts.can
     grid columnconfigure $top.buts 0 -weight 1 -uniform a
     grid columnconfigure $top.buts 1 -weight 1 -uniform a
     grid $top.buts - - -pady 10 -sticky ew
+    bind $top <Visibility> "focus $top.buts.ok"
 }
 
 proc choosecolor {v vi w x cmd} {