use realtime signals instead of SIGUSR1
use realtime signals instead of SIGUSR1

Ignore-this: 73239c3bde366794e026b40632be397e

darcs-hash:20101123022205-c41ad-9a8584895f22cbfc51444d003132ab3761f9b845

janestreet/lwt-async,c-cube/lwt,c-cube/lwt,mfp/lwt,rneswold/lwt,rgrinberg/lwt,gfxmonk/lwt,janestreet/lwt-async,ocsigen/lwt,gfxmonk/lwt,rgrinberg/lwt,ocsigen/lwt,rgrinberg/lwt,rneswold/lwt,mfp/lwt,c-cube/lwt,fdopen/lwt,mirage/lwt,rneswold/lwt,mirage/lwt,ocsigen/lwt,fdopen/lwt,rgrinberg/lwt