Bug fix: absolute and absolute indexed fetched wrong address
Bug fix on shift operations again. Other macros broke T0.
Bug fix: manage r12 correctly, and TXS used a wrong register

To use r12 in assembly code:
 - use -fomit-frame-pointer for test.c
 - save and restore on calling libc functions
Add some I/O and memory emulation to check Apple2 BASIC
Bug fix: adc and sbc performed wrong carry flag calculation
Bug fix: toAbsb can not store the right value
Use 6502_65C02_functional_tests, and two bug fixes
 - transfer operations should update n and z flags
 - TSX should transfer SP, not SR
Bug fix: after TSX, X got a value >= 0x100
Bug fix: B and reserved flag should not be modified on updating SR
Bug fix: INX did not store the result correctly
Bug fix: BRK should set I flag
Bug fix: conditions are hard :(
Bug fix: stack is hard :(
  SP should wrap correctly on push and pop
Bug fix: TSX was still wrong
Bug fix: data was broken on absolute and absolute indexed destination

Now it can show "Apple ][" logo by using Apple BASIC ROM!!