some bug fixes

[Fifer, Eric]

>I don't understand your select patch, so I'm not going to check it in.

I was just porting some code that happened to do a select
to check exceptions on stdout.  In this case peek_pipe was
failing with an error, but the error was really due to PeekNamedPipe
being used with the write end of a pipe.  So, it was failing with
ACCESS_DENIED because GENERIC_READ was not one of the create options
on the handle.  Anyway, I just added a check to see if peek_pipe
was looking at the write end of a pipe.  I tried to check the
device against FH_PIPEW, but unfortunately it is only set to
the more generic FH_PIPE (not FH_PIPER, or FH_PIPEW).

Thanks.

Eric