Defines starting with `c' in netccitt

• CALL netccitt/pk.h:176
• CALL_ACCEPTED netccitt/pk.h:177
• CCITTPROTO_HDLC netccitt/x25.h:49
• CCITTPROTO_X25 netccitt/x25.h:50
• CLEAR netccitt/pk.h:178
• CLEAR_CONF netccitt/pk.h:179