Patch from Mato that fixes a subtle connect bug: EAGAIN was being used as a translation value for EINPROGRESS, thus
shadowing a real EAGAIN return value from the OS.  This caused later
assertions of "Invalid argument" in stream_engine.cpp when it attempted to
use a socket which was not connected.

I also add EINTR to mean EINPROGRESS, as per the POSIX and FreeBSD
documentation which specifies that a connect() call interrupted due to a
signal will complete asynchronously.
Signed-off-by: Martin Lucina <martin@lucina.net>