git-gui: Bind n/c/o accelerators in repository chooser

On Windows we need to actually setup binds for the accelerator
keys, otherwise the OS doesn't respond to them when the user
presses the key combinations.  Apparently we automatically get
these on Mac OS X when we configure the menu commands, but not
on Windows.

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

lib/choose_repository.tcl

@@ -84,6 +84,8 @@ constructor pick {} {
 			-command [cb _next new] \
 			-accelerator $M1T-N \
 			-label [mc "New..."]
+		bind $top <$M1B-n> [cb _next new]
+		bind $top <$M1B-N> [cb _next new]
 	}
 
 	$opts tag conf link_clone -foreground blue -underline 1
@@ -95,6 +97,8 @@ constructor pick {} {
 			-command [cb _next clone] \
 			-accelerator $M1T-C \
 			-label [mc "Clone..."]
+		bind $top <$M1B-c> [cb _next clone]
+		bind $top <$M1B-C> [cb _next clone]
 	}
 
 	$opts tag conf link_open -foreground blue -underline 1
@@ -106,6 +110,8 @@ constructor pick {} {
 			-command [cb _next open] \
 			-accelerator $M1T-O \
 			-label [mc "Open..."]
+		bind $top <$M1B-o> [cb _next open]
+		bind $top <$M1B-O> [cb _next open]
 	}
 
 	$opts conf -state disabled