fix bindbackend build with new automake versions

  new automake versions generate .hh from .yy with yacc,
  older versions generate .h

  copy the .hh -> .h rule from pdns/Makefile.am
fix bindparser reduce conflicts

resolve reduce conflicts to what yacc defaulted to:

  * 'root_command' included 'command' directly and through
    'options_command' and 'zone_command'; separate option/zone commands
    for global usage, which don't include 'command' anymore.
  * 'command' included 'also_notify' and 'zone_also_notify'; yacc resolved
    conflict by defaulting to 'also_notify'; removed 'zone_also_notify'
    from global zone commands.