Box type improvements/fixes

fix not clearing type selector when selecting new object to edit
fix no undo action for selecting type
add sides_flat option where right/back/bottom sides are mirrored to match up with left/front/top sides (good for 0-width faces)
improved code for setting box UVs (109 less lines of code AFTER adding another new type!)

Author: FirEmerald

src/main/java/firemerald/mcms/Main.java

@@ -81,8 +81,8 @@
 public class Main
 {
 	public static final String ID = "mcms";
-	public static final String VERSION = "0.2.2";
-	public static final String BUILD_DATE = "04/01/2022 21:49";
+	public static final String VERSION = "0.2.3";
+	public static final String BUILD_DATE = "04/01/2022 22:43";
 	public static final Logger LOGGER = LogManager.getLogger("MCMS"); //the main logger;
 	public static Main instance;
 	public static final int MIN_W = 640, MIN_H = 480;