Fix simple_decorator and basictag not setting __module__.

Review Request #7736 — Created Oct. 25, 2015 and submitted — Latest diff uploaded

Information

Djblets
release-0.8.x

Reviewers

These decorators weren't setting __module__, which, while mostly
harmless, did result in Sphinx filtering out any functions decorated by
these two decorators.

We now use update_wrapper() from functools, which sets all the
attributes we need.

All Djblets and Review Board unit tests pass.