[bgpd] Fixed as-path prepend/exclude ASN handling

 - aspath_gettoken(): use as_t to fix 4-byte ASN scanning (bug #484)
 - set_aspath_prepend_cmd(): use CMD_AS_RANGE in message to match
   actual range
 - no_set_aspath_prepend_val_cmd(): idem
 - set_aspath_exclude_cmd(): idem
 - no_set_aspath_exclude_val_cmd(): idem
2 files changed