perf timechart: Add more options to IO mode

--io-skip-eagain - don't show EAGAIN errors
--io-min-time    - make small io bursts visible
--io-merge-dist  - merge adjacent events

Signed-off-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/1404835423-23098-5-git-send-email-stfomichev@yandex-team.ru


Signed-off-by: Jiri Olsa <jolsa@kernel.org>