* fhandler_socket.cc (fhandler_socket::evaluate_events): Make erase

	* fhandler_socket.cc (fhandler_socket::evaluate_events): Make erase
	const in parameter list.
	(fhandler_socket::wait_for_events): Take a DWORD flags value instead of
	just a bool.  Call evaluate_events with erase flag according to
	MSG_PEEK value in flags.  Replace check for dontwait with check for
	MSG_DONTWAIT in flags.
	(fhandler_socket::connect): Call wait_for_events with 0 flags value.
	(fhandler_socket::accept4): Ditto.
	(fhandler_socket::recv_internal): Save flags in wait_flags.  Drop
	dontwait variable.  Call wait_for_events with wait_flags.
	(fhandler_socket::send_internal): Save MSG_DONTWAIT flag in wait_flags
	and call wait_for_events with wait_flags as argument.  Drop dontwait
	variable.
	* fhandler.h (class fhandler_socket): Change second parameter in
	declaration of wait_for_events to const DWORD.