Bug Fixes and Copyright Date Change

The simulator now passes Klaus Dormann's 6502 Functional Test suite for
the first time.

Bug Fixes:

- PHP was not correctly setting the Break bit on the stack copy of the
  processor status, so subsequent PLA's would not set the Break status
  flag.

- The CPU had swapped NMI and IRQ reset vectors, so RTI was failing.

- BRK was pushing PC + 2 onto the stack, instead of PC + 1

- (Zero Page,X) addressing mode did not correctly wrap on zero page
  boundaries.

- The instruction table used for disassembly had addressing modes
  of LDA $B9 and $BD reversed. This did not affect behavior, only
  disassembly of these instructions.

Other:

- Updated copyright date for 2013.

- Started migrating old JUnit 3 style tests to JUnit 4 annotations.