Adds Undershirts [Merge dis]

Sprites by MrSnapwalk mainly

They are in the Preview
They are on your Random'd characters
They are in Game
They are in your save files
They are changeable via clicking on a Dresser
They make you sexy, too sexy for your shirt, so sexy it hurts.

(Yes I know I said I'd port the bay ones but they're really really different to how we do things, so coded from scratch)

Also removed the FILE_DIRs, Again.