Note on upstream/1.1.0 import empty commits

The weird git version checked in here (0.0~git20130321.1.433265f) is
actually the 1.1.0 release. However, there's nothing in the repo
indicating this, and hence building this package would be confusing for
Clojure Team members without that knowledge.

I have checked the orig tarball for 1.1.0 into the pristine-tar branch,
which was missing. I also did a no-op import in order to avoid confusion
on the version of the upstream source in git. The upstream/1.1.0 tag
previously referred to an orphaned import of the 1.1.0 source code, so I
have replaced it with a tag that points to the upstream branch import.