* cdl/io_can.cdl: support for add/remove compiler flags * doc/can.sgml, doc/can_driver_doc.html: updated doc reflecting API changes (range/mask filtering, listen-only mode, return values for xmt_msg/rcv_event, new flags). * include/can.h: given in a match the types of function pointers for can_callbacks_t according to the changes made in can.c. * include/canio.h: flags field in event enlarged to 32 bits to fit new events 'CYGNUM_CAN_EVENT_ERR_ACTIVE' and 'CYGNUM_CAN_EVENT_OVERRUN_RX_HW'. Made a 'flag' typedef. cyg_can_event fields reordered so flags size change keeps events the same size. Defined new filtering capabilities (range/mask). New convenience macro CYGNUM_CAN_EVENT_ALL. New listen-only mode. * src/can.c: can_rcv_event() and can_xmt_msg() now returns cyg_bool (were 'void'). flags using cyg_can_event_flags_t type. [ Bugzilla 1001453 ]