Make logging work for MI.

	Make logging work for MI.
	* NEWS: Mention it.
	* interps.h (interp_set_logging_ftype): New typedef.
	(struct interp_procs): New field set_logging_proc.
	(current_interp_set_logging): Declare.
	* interps.c (current_interp_set_logging): New function.
	* cli/cli-logging.c: Include interps.h.
	(set_logging_redirect): Call current_interp_set_logging.
	(pop_output_files): Ditto.
	(handle_redirections): Ditto, plus skip ui-out redirect if MI.
	* mi/mi-console.h (mi_console_set_raw): Declare.
	* mi/mi-console.c (mi_console_set_raw): New function.
	* mi/mi-interp.c (saved_raw_stdout): New global.
	(mi_set_logging): New function.
	(_initialize_mi_interp): Add it to interp procs.

	* gdb.mi/mi-logging.exp: New file.