Merge branch 't/afh_receiver'

Merge branch 't/afh_receiver'

	57d75e play: Fix segfault if decoder is not supported.
	98f192 Interactive support depends on curses lib.
	3e3d8e para_play, implementation.
	d02f88 para_play, infrastructure.
	3b2ee2 Make writer nodes honor notifications.
	e541d7 interactive: Introduce i9e_print_status_bar().
	901f66 interactive: Implement single key mode.
	6cb789 interactive: Add producer to struct i9e_client_info.
	c31982 Interactive: Introduce i9e_get_error().
	be1074 interactive: Fix wipe_bottom_line() on MacOS.
	3ba772 interactive: Honor SIGWINCH.
	56561c interactive: Honor SIGTERM.
	06f33c para_afh: remove streaming mode.
	4a30c5 The afh receiver, documentation.
	b84e37 The afh receiver, implementation.
	618a25 The afh_receiver, infrastructure.
	4fa8cb Add execute mechanism to receiver nodes.
	7c8931 Introduce afh_get_afhi_txt().
	3f1510 audiod: Replace kill_btrn() by task notifications.
	5edb8f sched: Replace sched_shutdown() by task_notify_all().
	58ce61 sched: Introduce task notifications.
	b56199 i9e_attach_to_stdout(): Don't insist on btrn == NULL.
	7867cd Interactive: Assorted whitespace/newline fixes.
	b654be interactive: kill i9ep->line_handler_running.
	77b607 interactive: Do not close stderr in i9e_close().
	099ef4 Add missing documentation of send_strerror().

Conflicts:
	osx_write.c