[NaCl SDK] Store python coverage output data in 'out' directory

[NaCl SDK] Store python coverage output data in 'out' directory

Also add --quick argument to test_all.py that excludes
large tests (those that take seconds rather than ms).

Committed: https://crrev.com/d3de957a73d7553233a5812a4cac8fa515fe43ea
Cr-Commit-Position: refs/heads/master@{#310481}

[Sam Clegg, 2015-01-07 11:50:42]

sbc@chromium.org changed reviewers:
+ binji@chromium.org

[binji, 2015-01-07 18:46:02]

lgtm

[Sam Clegg, 2015-01-08 11:10:37]

The CQ bit was checked by sbc@chromium.org

[commit-bot: I haz the power, 2015-01-08 11:11:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/835773003/1

[commit-bot: I haz the power, 2015-01-08 11:55:12]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-08 11:56:04]

Patchset 1 (id:??) landed as
https://crrev.com/d3de957a73d7553233a5812a4cac8fa515fe43ea
Cr-Commit-Position: refs/heads/master@{#310481}