add more tests for Lwt_stream.clone ( and expose a bug )
add more tests for Lwt_stream.clone ( and expose a bug )

Ignore-this: 844e0ea4b6ecf8c4e2a802cc1e755aa4

darcs-hash:20100217183429-0cb73-023c47fd2d0331cc1030f62132118a0a19acbf46

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