jstorm-runner: support SourceMetrics, distribution metrics, and saves MetricsResults after cancelling.

[peihe]

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[peihe]

R: @bastiliu

[coveralls]

Changes Unknown when pulling 77d486a on peihe:jstorm-runner-9 into ** on apache:jstorm-runner**.

[bastiliu]

LGTM.
Just a minor comment. The Histogram in JStorm keeps a reservoir with fixed records. It means the values of Histogram snapshot is not very accurate to calculate the sum and count of distribution metrics. If we didn't have a better solution now, I think it is OK to leave a TODO here for further improvement.

[peihe]

Added TODO

+R: @JingsongLi

[coveralls]

Changes Unknown when pulling 599db6b on peihe:jstorm-runner-9 into ** on apache:jstorm-runner**.

[coveralls]

Changes Unknown when pulling 0a457b5 on peihe:jstorm-runner-9 into ** on apache:jstorm-runner**.

[peihe]

retest this please

[peihe]

retest this please

[coveralls]

Changes Unknown when pulling 0a457b5 on peihe:jstorm-runner-9 into ** on apache:jstorm-runner**.

[JingsongLi]

LGTM

[peihe]

Thanks, Jingsong!

[peihe]

merged