Tiptoi/TING-Codetester

- calculate checksum for TING-Codes (as described here:
http://www.mikrocontroller.net/topic/214479#2973275)
- experimental: calculate checksum for Tiptoi-Codes (TING-Checksum XOR
0x02)
- visualize code by decimal/binary value
- calculate decimal/binary value from visualized code

Notice: Decimal value and code value are not identical and can't be
calculated from each other by now (see
http://www.mikrocontroller.net/topic/214479#2973215).
Merge pull request #32 from ToniMahagoni/master

Tiptoi/TING-Codetester