Fix multiplayer leave dialog not working on all exit operations
FindProvider
AllSources
ISkinSource
Align label widths of editor setup screen controls
SkinProvidingContainer
Currently `protected` functionality for use in custom `SkinProvidingContainer`s, can be exposed to public constructors if it need to later on, but I'm not sure about doing that opposed to just nesting multiple `SkinProvidingContainer`.
LegacySkinTransformer
ISkin
Improve hit error judgement displays
LabelledDrawable