More UI changes, made weapons usable, fixed ammo for turret types

core/src/io/anuke/mindustry/Vars.java

@@ -15,6 +15,8 @@ public class Vars{
 	public static final float respawnduration = 60*4;
 	//time between waves in frames
 	public static final float wavespace = 35*60*(android ? 2 : 1);
+	//waves can last no longer than 6 minutes, otherwise the next one spawns
+	public static final float maxwavespace = 60*60*6;
 	//how far away from spawn points the player can't place blocks
 	public static final float enemyspawnspace = 65;
 	//scale of the font