Smooth doors + multi-tile door code tweaks (#3365)

-Changes almost all of door opening/closing animations to be smooth. Also adjusts some door sprites so they actually can be opened smoothly.
-Fixes minor problems with some door sprites. Usually only few pixels.
-Adds "o_door_open" opened state with panel open to common glass door, lift door and vault door, since these have visible panel even while opened. EDIT: They will now show up correctly when needed. Added a var used to mark doors with panels visible while open.
-Adds opening/closing animations "door_closing_stat" and "door_opening_stat" with lights off to doors that did not have it. EDIT: Should now correctly show up when the door is forced manually.
-Removes many unused duplicate dmi files and icon states in door file.
-Adds new dmi file in doors folder containing misc door overlays. Not used anywhere, purely for reference and spriting.
-Changes the multi-tile airlock to have 4 directions instead of 2. Also makes it correctly update hatches for those directions when moved or built from scratch.
-Adds vault assembly. It can be built like any other door, but it costs 10 sheets instead of 4 and takes double the time to make, since it has double explosion resistance and lot more health.
-Adds elevator door assembly along with icon states into the code. It is currently unused, because I have yet to figure out how to make building lift-doors work, and that will not be included in this PR.

code/game/objects/structures/door_assembly.dm

@@ -101,12 +101,24 @@
 	airlock_type = "/maintenance_hatch"
 	glass = -1
 
-/obj/structure/door_assembly/door_assembly_highsecurity // Borrowing this until WJohnston makes sprites for the assembly
+/obj/structure/door_assembly/door_assembly_highsecurity
 	base_icon_state = "highsec"
 	base_name = "High Security Airlock"
 	airlock_type = "/highsecurity"
 	glass = -1
 
+/obj/structure/door_assembly/door_assembly_vault
+	base_icon_state = "vault"
+	base_name = "Vault"
+	airlock_type = "/vault"
+	glass = -1
+
+/obj/structure/door_assembly/door_assembly_lift
+	base_icon_state = "lift"
+	base_name = "Elevator Door"
+	airlock_type = "/lift"
+	glass = -1
+
 /obj/structure/door_assembly/multi_tile
 	icon = 'icons/obj/doors/door_assembly2x1.dmi'
 	dir = EAST