Add release notes for Djblets 0.9.4.
Review Request #8452 — Created Oct. 10, 2016 and submitted
This covers the new DMARC support, extension unit testing additions, and other improvements made since 0.9.3.
Built the docs and went through them, verifying that links worked
and the items matched what's in the commit history.
Tool: Pyflakes Ignored Files: docs/djblets/guides/extensions/testing-extensions.rst docs/releasenotes/index.rst docs/releasenotes/0.9.4.rst AUTHORS Tool: PEP8 Style Checker Ignored Files: docs/djblets/guides/extensions/testing-extensions.rst docs/releasenotes/index.rst docs/releasenotes/0.9.4.rst AUTHORS