Custom() detects window close

Signed-off-by: Jeff Carr <jcarr@wit.com>

new.go

@@ -1,6 +1,7 @@
 package repostatus
 
 import 	(
+	"go.wit.com/log"
 	"go.wit.com/gui/gui"
 	"go.wit.com/gui/gadgets"
 )
@@ -18,5 +19,9 @@ func New(p *gui.Node, path string) *RepoStatus {
 	rs.window.Make()
 	rs.ready = true
 	rs.draw()
+	rs.window.Custom = func() {
+		rs.hidden = true
+		log.Warn("repostatus user closed the window()")
+	}
 	return rs
 }