Bugfixes and refactoring

Bugfixes:

 - Fixes a bug which placed the tree dots (…) for overflown list on the wrong position.

Refactoring

 - Renamed `TextRender` to `TextRenderer`
 - Renamed `NoopRenderer` to `PlainRenderer`
 - Renamed `NoopRendererFactory` to `PlainRendererFactory`

example/coloredList.go

@@ -19,8 +19,8 @@ func commonList() *termui.List {
 
 	list := termui.NewList()
 	list.Items = strs
-	list.Height = 20
-	list.Width = 25
+	list.Height = 15
+	list.Width = 26
 	list.RendererFactory = termui.MarkdownTextRendererFactory{}
 
 	return list