git-gui: Allow specifying an initial line for git gui blame.

Add a command-line option to make git gui blame automatically
scroll to a specific line in the file. Useful for integration
with other tools.

Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

lib/browser.tcl

@@ -151,7 +151,7 @@ method _enter {} {
 				append p [lindex $n 1]
 			}
 			append p $name
-			blame::new $browser_commit $p
+			blame::new $browser_commit $p {}
 		}
 		}
 	}