Lengthen lastchange VERSION string to show full hash and commit position.

Lengthen lastchange VERSION string to show full hash and commit position.

Now that the DMServer has been fixed to accept 'agent' strings longer than
64 characters (http://crbug.com/406948), we can re-lengthen the string
produced by lastchange.py to include both the full git hash and the
Cr-Commit-Position.

R=joaodasilva@chromium.org, scottmg@chromium.org
BUG=406783
Committed: https://crrev.com/740c00432f11b2378fcb2cc72e09dd0c9a74e62f
Cr-Commit-Position: refs/heads/master@{#292963}

[scottmg, 2014-09-02 17:05:24]

lgtm

[agable, 2014-09-02 17:24:04]

The CQ bit was checked by agable@chromium.org

[commit-bot: I haz the power, 2014-09-02 17:25:14]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/agable@chromium.org/527103004/1

[commit-bot: I haz the power, 2014-09-02 18:35:22]

Committed patchset #1 (id:1) as 091a8710b85587017b1abade341d61084fdbb5ef

[commit-bot: I haz the power, 2014-09-10 03:19:36]

Patchset 1 (id:??) landed as
https://crrev.com/740c00432f11b2378fcb2cc72e09dd0c9a74e62f
Cr-Commit-Position: refs/heads/master@{#292963}