* fhandler_dsp.cc (fhandler_dev_dsp::Audio): Add fh member.

	* fhandler_dsp.cc (fhandler_dev_dsp::Audio): Add fh member.
	(fhandler_dev_dsp::Audio_out::Audio_out): Take pointer to encapsulating
	fhandler_dev_dsp as parameter.
	(fhandler_dev_dsp::Audio_in::Audio_in): Ditto.
	(fhandler_dev_dsp::Audio::Audio): Take pointer to encapsulating
	fhandler_dev_dsp as parameter and store in fh.
	(fhandler_dev_dsp::Audio_out::write): Change return type to int and
	return number of bytes written.  Return -1 if waitforspace returns false
	and no bytes have been written so far.
	(fhandler_dev_dsp::Audio_out::waitforspace): Change return type to bool.
	Handle O_NONBLOCK.  Make waiting loop interruptible and cancelable.
	Return false in any of these cases, otherwise true.
	(fhandler_dev_dsp::Audio_in::read): Set returned nBytes to -1 if
	waitfordata returns false and nothing has been read so far.
	(fhandler_dev_dsp::Audio_in::waitfordata): Change return type to bool.
	Handle O_NONBLOCK.  Make waiting loop interruptible and cancelable.
	Return false in any of these cases, otherwise true.
	(fhandler_dev_dsp::write): Call Audio_out constructor with this as
	parameter.
	(fhandler_dev_dsp::read): Call Audio_in constructor with this as
	parameter.