Fix TabbedContainer not setting tags correctly

heading.go

@@ -23,3 +23,9 @@ func NewHeading (level int, text string) *Heading {
 	return this
 }
 
+// NewMenuHeading creatss a new heading for use in menus.
+func NewMenuHeading (text string) *Heading {
+	heading := NewHeading(0, text)
+	heading.SetTag("menu", true)
+	return heading
+}

tabbedcontainer.go

@@ -126,10 +126,10 @@ type tab struct {
 func (this *tab) setActive (active bool) {
 	if active {
 		this.SetRole(tomo.R("objects", "Tab"))
-		this.SetTag("active", false)
+		this.SetTag("active", true)
 	} else {
 		this.SetRole(tomo.R("objects", "Tab"))
-		this.SetTag("active", true)
+		this.SetTag("active", false)
 	}
 }