Make queries for auto_generated work with older CLs

Older Message entities in the datastore have no value for auto_generated, so they will not match a query for either auto_generated == True or a query for auto_generated == False.   To get the ones that are not auto_generated, you have to do auto_generated != True.  To complicate things a bit, using != is restricted in GAE datastore queries to be only on one property and only the same as any sort directive.  So, for approvals/disapprovals, I did post-filtering.

The reviewer_approval field is computed and then stored, so there will be some CLs that have the all black and no green/red links displayed until each of those CLs gets another comment added after this fix is deployed. 

Also, I checked https://groups.google.com/a/chromium.org/forum/#!forum/chromium-reviews and it looks like we sent out some extra diffs today, but I don't think anyone will really care, especially because duplicates are displayed collapsed in gmail and google groups.

[jrobbins (corp), 2014-09-03 02:22:21]

The index.yaml change is just an automatic change resulting from when I ran the
app locally.  It should have no effect.  Let me know if you spot anything wrong
with it.

[rmistry, 2014-09-03 11:29:54]

LGTM

Thanks for the quick fix!
Let me know when it is staged, I will help test it.

https://codereview.appspot.com/137090043/diff/1/codereview/models.py
File codereview/models.py (right):

https://codereview.appspot.com/137090043/diff/1/codereview/models.py#newcode281
codereview/models.py:281: # and (b) auto_generated != False conflicts with
sorting.
I think you meant to invert the booleans in this comment:

(a) auto_generated == False does not return legacy messages
(b) auto_generated != True conflicts with sorting

[jrobbins (corp), 2014-09-03 13:56:43]

Committed and deployed for testing at
https://1433-109a53420dcd-dot-chromiumcodereview-hr.appspot.com/


On Wed, Sep 3, 2014 at 4:29 AM, <rmistry@google.com> wrote:

> LGTM
>
> Thanks for the quick fix!
> Let me know when it is staged, I will help test it.
>
>
> https://codereview.appspot.com/137090043/diff/1/codereview/models.py
> File codereview/models.py (right):
>
> https://codereview.appspot.com/137090043/diff/1/codereview/models.py#
> newcode281
> codereview/models.py:281: # and (b) auto_generated != False conflicts
> with sorting.
> I think you meant to invert the booleans in this comment:
>
> (a) auto_generated == False does not return legacy messages
> (b) auto_generated != True conflicts with sorting
>
> https://codereview.appspot.com/137090043/
>