Fix DSKey encoding.

Fix DSKey encoding.

Specifically, IntID's always sort before StringID's. This is according to
https://cloud.google.com/appengine/docs/go/datastore/queries#Go_Key_filters

R=dnj@chromium.org, estaab@chromium.org, vadimsh@chromium.org
BUG=

Committed: https://chromium.googlesource.com/infra/infra/+/ca9bcb2b4df7d32b8fde4b8ad4928dd3d368142e

[dnj (Google), 2015-07-18 17:13:33]

dnj@google.com changed reviewers:
+ dnj@google.com

[dnj (Google), 2015-07-18 17:13:34]

lgtm

[iannucci, 2015-07-18 17:14:05]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2015-07-18 17:14:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1231863018/20001

[commit-bot: I haz the power, 2015-07-18 17:14:18]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-18 17:14:19]

No L-G-T-M from a valid reviewer yet. Only full committers are accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[dnj, 2015-07-18 17:16:57]

On 2015/07/18 17:14:19, commit-bot: I haz the power wrote:
> No L-G-T-M from a valid reviewer yet. Only full committers are accepted.
> Even if an L-G-T-M may have been provided, it was from a non-committer,
> _not_ a full super star committer.
> See http://www.chromium.org/getting-involved/become-a-committer
> Note that this has nothing to do with OWNERS files.

lgtm (from @chromium, I really need to track that bug down...)

[iannucci, 2015-07-19 18:20:03]

The CQ bit was checked by iannucci@chromium.org

[commit-bot: I haz the power, 2015-07-19 18:20:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1231863018/20001

[commit-bot: I haz the power, 2015-07-19 18:22:35]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/infra/infra/+/ca9bcb2b4df7d32b8fde4b8ad4928...