gitweb: Add link to other blame implementation in blame views

Add link to 'blame_incremental' action (which requires JavaScript) in
'blame' view, and add link to 'blame' action in 'blame_incremental'
view.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

gitweb/gitweb.perl

@@ -4883,6 +4883,17 @@ sub git_blame_common {
 	my $formats_nav =
 		$cgi->a({-href => href(action=>"blob", -replay=>1)},
 		        "blob") .
+		" | ";
+	if ($format eq 'incremental') {
+		$formats_nav .=
+			$cgi->a({-href => href(action=>"blame", javascript=>0, -replay=>1)},
+			        "blame") . " (non-incremental)";
+	} else {
+		$formats_nav .=
+			$cgi->a({-href => href(action=>"blame_incremental", -replay=>1)},
+			        "blame") . " (incremental)";
+	}
+	$formats_nav .=
 		" | " .
 		$cgi->a({-href => href(action=>"history", -replay=>1)},
 		        "history") .