Add try release mode to test runner.

Add try release mode to test runner.

Also refactor the configuration of modes to have the level
of abstraction in one json dict.

In a follow up CL, the new mode could be added to quickcheck
and release trybots.

Committed: https://crrev.com/7a8d0c02a5e3e9996ebfdabfb953fd787e4dd3d2
Cr-Commit-Position: refs/heads/master@{#26322}

[Michael Achenbach, 2015-01-28 14:07:09]

machenbach@chromium.org changed reviewers:
+ jkummerow@chromium.org, jochen@chromium.org

[Michael Achenbach, 2015-01-28 14:10:05]

PTAL

https://codereview.chromium.org/882983002/diff/1/tools/run-tests.py
File tools/run-tests.py (right):

https://codereview.chromium.org/882983002/diff/1/tools/run-tests.py#newcode119
tools/run-tests.py:119: "status_mode": "debug",
Use debug as status mode as release with slow asserts requires most of the
skip/slow configurations like tests in debug where slow asserts are enabled by
default.

[Jakob Kummerow, 2015-01-28 14:48:22]

lgtm

[Michael Achenbach, 2015-01-29 09:52:35]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2015-01-29 09:53:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/882983002/1

[commit-bot: I haz the power, 2015-01-29 10:23:04]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-29 10:23:06]

Patchset 1 (id:??) landed as
https://crrev.com/7a8d0c02a5e3e9996ebfdabfb953fd787e4dd3d2
Cr-Commit-Position: refs/heads/master@{#26322}