update the manual about lwt.react
update the manual about lwt.react

Ignore-this: b6e0ecc17e9933dcc70b777ce55e3a58

darcs-hash:20110311095543-c41ad-da2fd7651d59732232cda88de9b33895701d6e5a

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