First work toward moving to a Swing UI for the simulator.

src/main/java/com/loomcom/symon/exceptions/MemoryRangeException.java

@@ -3,7 +3,7 @@ package com.loomcom.symon.exceptions;
 /**
  * Exception that will be thrown if devices conflict in the IO map.
  */
-public class MemoryRangeException extends Exception {
+public class MemoryRangeException extends SymonException {
   public MemoryRangeException(String msg) {
     super(msg);
   }