ui/layout,ui/app: fix tests, go fmt, update comments

Signed-off-by: Elias Naur <mail@eliasnaur.com>

ui/layout/layout_test.go

@@ -149,6 +149,6 @@ func (config) Px(v ui.Value) int {
 	return int(v.V + .5)
 }
 
-func (queue) Next(k ui.Key) (ui.Event, bool) {
-	return nil, false
+func (queue) Events(k ui.Key) []ui.Event {
+	return nil
 }

ui/layout/list.go

@@ -66,7 +66,7 @@ const (
 
 const inf = 1e6
 
-// Init prepares the list for iterating through its children with Next.
+// init prepares the list for iterating through its children with next.
 func (l *List) init(gtx *Context, len int) {
 	if l.more() {
 		panic("unfinished child")