Add support to pushing unstable changes for the chrome pfq.

Add support to pushing unstable changes for the chrome pfq.

This specifically gets the pfq one step closer to being completely ready to rev.  We add --noprebuilts for the chrome pfq as its not ready to host prebuilts and instead we push unstable ebuilds.  Anush noticed an Anush today where we are revving even when we don't change, and I've addressed this also in this CL.

Specifically:

1)  Sort in cbuildbot long options by long format
2)  Add --noprebuilts so that the Chrome PFQ can use this for now.
3)  Fixed a unittest that had broken in a previous CL for cros_mark_chrome_as_stable.
4)  Add ability for chrome to only rev if something really has changed:

 -- This means, if the new ebuild either:
  -- doesn't have the exact same chrome_version
  -- or diff -Bu (actual diff) between last ebuild and new ebuild isn't the same (i.e. detecting a 9999 change or different CROS_SVN_COMMIT)

Change-Id: I9b289c2168d6868299573f5d7c7a676380ee497e

BUG=chromium-os:8693
TEST=Ran unittests (cbuildbot, cros_mark_*) and ran cbuildbot with new chrome pfq items.

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=d8a0a57

[sosa, 2010-12-10 06:06:02]

anush/cmasone for cros_mark_chrome_* changes.
david for cbuildbot and cros_mark_as_stable change.

[Chris Masone, 2010-12-10 16:31:23]

parts I was to review lgtm

http://codereview.chromium.org/5783001/diff/8001/bin/cros_mark_chrome_as_stab...
File bin/cros_mark_chrome_as_stable.py (right):

http://codereview.chromium.org/5783001/diff/8001/bin/cros_mark_chrome_as_stab...
bin/cros_mark_chrome_as_stable.py:266: make_stable=False)
Is this last arg temporary?  If so, a comment to that effect would be helpful

[sosa, 2010-12-10 23:44:07]

Hey scott can you take a look at the cbuildbot changes?

[davidjames, 2010-12-10 23:52:38]

LGTM for cbuildbot and cros_mark_as_stable change.

[scottz, 2010-12-11 00:05:36]

LGTM

http://codereview.chromium.org/5783001/diff/8001/bin/cros_mark_chrome_as_stab...
File bin/cros_mark_chrome_as_stable.py (right):

http://codereview.chromium.org/5783001/diff/8001/bin/cros_mark_chrome_as_stab...
bin/cros_mark_chrome_as_stable.py:272: redirect_stdout=True,
redirect_ should be aligned with exit_code.