Cygwin: FIFO: add a timeout to take_ownership

Cygwin: FIFO: add a timeout to take_ownership

fhandler_fifo::take_ownership() is called from select.cc::peek_fifo
and fhandler_fifo::raw_read and could potentially block indefinitely
if something goes wrong.  This is always undesirable in peek_fifo, and
it is undesirable in a nonblocking read.  Fix this by adding a timeout
parameter to take_ownership.

Arbitrarily use a 1 ms timeout in peek_fifo and a 10 ms timeout in
raw_read.  These numbers may have to be tweaked based on experience.

Replace the call to cygwait in take_ownership by a call to WFSO.
There's no need to allow interruption now that we have a timeout.