* mon960-rom.c: New file; support mon960 rom monitor on i960.

   * mon960-rom.c: New file; support mon960 rom monitor on i960.
       * monitor.c (monitor_debug): Change remotedebug to buffer strings.
       * monitor.c (monitor_open): Add test for flag MO_NO_ECHO_ON_OPEN before
       epecting prompt and echo during open.
       * monitor.c (monitor_stop): Add test for flag MO_SEND_BREAK_ON_OPEN to
       determine if break should be sent as stop command.
       * monitor.h: Add flags MO_NO_ECHO_ON_OPEN and MO_SEND_BREAK_ON_OPEN.
       * i960-tdep.c (mon960_frame_chain_valid): New function for getting
       stack frame on mon960.
       * Makefile.in: Add mon960 files.
       * configure.in: Changed i960-*-coff* and i960-*-elf* to target mon960;
       added i960-nindy-coff* and i960-nindy-elf* for target nindy.
       * configure: Regenerated.
       * config/i960/mon960.mt, config/i960/tm-mon960.h: New files;
       support mon960 rom monitor on i960.