Fixes and enhancements.

- Added ability to change inner border width of console window.
- Fixed a nasty bug that prevented key press handling.
- Reset now clears the accumulator and index registers.

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

@@ -118,6 +118,11 @@ public class Cpu implements InstructionTable {
 
         // Reset step counter
         stepCounter = 0L;
+
+        // Reset registers.
+        a = 0;
+        x = 0;
+        y = 0;
     }
 
     public void step(int num) throws MemoryAccessException {