Update tools/upload.py from Rietveld's copy.

codereview.appspot.com now 301 redirects to HTTPS, which is probably
a good thing, but the version of upload.py we're using doesn't like it.

* Update tools/upload.py to the latest version from the Rietveld
  repository, since we haven't done so in ages:
  <http://code.google.com/p/rietveld/source/browse/upload.py?spec=svnf66cc9030489ea92a2e699a0f1a68a854f1d064c&r=f66cc9030489ea92a2e699a0f1a68a854f1d064c>
* Explicitly specify https: in appspot.py because even the new
  version of upload.py appears, from a quick review, to be defaulting to
  http:.
* upload.py has also renamed the fields of an issue; change appspot.py
  to match. 'Message' is now 'Title' and 'Description' is now 'Message'.
  Includes backwards compatibility for old .appspot-change files.

If you are reading this and it is not mangled, then uploading a review
using these changes to the tools worked.

@r5167

[felix8a, 2012-11-29 20:02:04]

lgtm