General:
- changed the implementation of open bus to something more accurate;
- code cleanup and refactoring.

CPU: Remade decoding arguments for opcodes that previously led to desynchronization and even crashes (like in Slalom).

Board:
- added mapper 16 (Bandai FCG-1/FCG-2/LZ93D50 (with 24C02);
- added mapper 41 (Caltron 6-in-1);
- added mapper 105 (NES-EVENT);
- added mapper 153 (Bandai LZ93D50 with SRAM);
- added mapper 159 (Bandai LZ93D50 with 24C01);
- added mapper 182;
- added mapper 193 (NTDEC TC-112);
- added mapper 200 (1200/36-in-1);
- added mapper 212;
- added mapper 214;
- added mapper 244.