Implemented a shadow copy of the RTC port value to enable multiple drivers to share the port without causing side effects to other drivers that use other bits of the RTC port.
- Added official support for Steve Cousin's RC2014 Z180 + Native Memory modules (SC111 & SC119). Thanks to Steve for his assistance with this.
- Improved interrupt framework to remove need to extra stubs for each IM2 interrupt handler.
Add periodic timer interrupt support for CTC platforms Easy Z80 and Zeta 2. Includes watchdog servicing for Easy Z80. Default interrupt mode for Easy Z80 and Zeta 2 is now IM2.
