An unknown name indexed the map, got undefined and drew nothing — the same
as no icon at all, so a typo was invisible. It resolves to a placeholder
glyph and the default tint now, and warns once per bad name: both lookups
sit in a render, so a bound widget would otherwise warn per value.
An empty name still draws nothing, which is what "no icon" means.
stroblme
59e942ca1c