gitk: Include commit title in branch dialog

Hi,

I made another branch dialog related change, included in this message.
It applies on top of my other two patches.

Rogier.

------- 8< ------------------- 8< --------------

Only the SHA1 was included. It's convenient to have the title
mentioned as well.

Signed-off-by: Rogier Goossens <goossens.rogier@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Author: Rogier Goossens

gitk

@@ -9484,7 +9484,7 @@ proc mvbranch {} {
 }
 
 proc branchdia {top valvar uivar} {
-    global NS
+    global NS commitinfo
     upvar $valvar val $uivar ui
 
     catch {destroy $top}
@@ -9497,6 +9497,11 @@ proc branchdia {top valvar uivar} {
     $top.sha1 insert 0 $val(id)
     $top.sha1 conf -state readonly
     grid $top.id $top.sha1 -sticky w
+    ${NS}::entry $top.head -width 60
+    $top.head insert 0 [lindex $commitinfo($val(id)) 0]
+    $top.head conf -state readonly
+    grid x $top.head -sticky ew
+    grid columnconfigure $top 1 -weight 1
     ${NS}::label $top.nlab -text [mc "Name:"]
     ${NS}::entry $top.name -width 40
     $top.name insert 0 $val(name)