Update to django 1.4.5.

I used the 1.4.5 tag in the django repo. This is essentially a no-op, but I figured it's easier on us if we're using the latest release. The conversations are like this:

"Hey, are we using the latest release?"

"Yes."

versus this:

"Hey, are we using the latest release?"

"No, but we're using 1.4.4 and 1.4.5 is just a no-op that they did because the 1.4.4 tarball had .pyc files in it which didn't affect us at all."

"Gee willikers!"

Quick r?