 - fix [ 642031 ] FATAL: Keyboard RESET error:993 again: rewrote keyboard    buffer cleanup - add BX_DEBUG_INT1A macro - change two "mov ax, #0000" to "xor ax, ax", so int70_handler does not overlap int08_handler
 - fix [ 642031 ] FATAL: Keyboard RESET error:993 again: rewrote keyboard
   buffer cleanup
- add BX_DEBUG_INT1A macro
- change two "mov ax, #0000" to "xor ax, ax", so int70_handler does not overlap int08_handler

dariaphoebe/bochs,dbrashear/bochs,dariaphoebe/bochs,dariaphoebe/bochs,dariaphoebe/bochs,dbrashear/bochs,dbrashear/bochs,dbrashear/bochs,dariaphoebe/bochs,dbrashear/bochs