Reworked labcoat buttoning

Changes labcoat code so buttoning and unbuttoning isn't done with a giant switch. Icon states for open and closed labcoats are now defined in the object itself as variables.

It functions exactly the same on the player end of things, but it is hopefully a little less silly on the code end of things and a lot more flexible for any sort of on-the-fly (read: admin-ish) things going on.
Nested absolute paths, why?

Side note: It'll work, due to how BYOND handles / as the first non-whitespace character in the line, but it doesn't look great.