- Adds "paintable" flag to pipe recipes so we know if we can paint it.
- Ports the RPD from Yawn Wider.
- Brings RPD sprites from /tg instead.
- Slightly refactors recipes to keep type-specifc vars on subtypes.
- Refactors RPD UI icons to use iconsheet assets: Instead of sending each individual icon to the client as needed, we declare an icon sheet asset and send the entire thing to client. Then we just use the given CSS classes to display the icons!
- Adds icon sheet asset datum for pipe and diposals construction.
