New UI layout, ROM loading, Font selection

- The UI layout has changed, and will likely change again in the future.

- Symon can now re-load ROM images from the File menu, under "Load ROM..."

- Font size can be changed under the "View" menu

src/main/java/com/loomcom/symon/Preferences.java

@@ -6,17 +6,17 @@ public interface Preferences {
 
     public static final int DEFAULT_PROGRAM_LOAD_ADDRESS = 0x0300;
 
-    public static final int DEFAULT_ACIA_ADDRESS = 0xc000;
-
     public static final int DEFAULT_BORDER_WIDTH = 10;
 
+    public static final boolean DEFAULT_HALT_ON_BREAK = true;
+
     public JDialog getDialog();
 
     public int getProgramStartAddress();
 
-    public int getAciaAddress();
-
     public int getBorderWidth();
 
+    public boolean getHaltOnBreak();
+
     public void updateUi();
 }