git-gui: Use arror cursor in blame viewer file data

Since we don't allow the user to select text from the file
viewer right now I'm disabling the normal text cursor and
putting in a plain arror instead.  This way users don't
think they can select and copy text, because they can't.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

lib/blame.tcl

@@ -38,6 +38,8 @@ variable group_colors {
 }
 
 constructor new {i_commit i_path} {
+	global cursor_ptr
+
 	set commit $i_commit
 	set path   $i_path
 
@@ -149,6 +151,7 @@ constructor new {i_commit i_path} {
 		$w_load \
 		$w_line \
 		$w_file] {
+		$i conf -cursor $cursor_ptr
 		$i conf -yscrollcommand \
 			[list many2scrollbar [list \
 			$w_cgrp \