Revert "Merge pull request #18 from hunner/release_0.5.0"

I didn't mention the upgrade of wordpress, or check what this would do to existing wordpress installations. Backing out unreleased.

This reverts commit 6019ee133ad10159722d01e54ce1a1cd08576d8e, reversing
changes made to a6b7afb97f251ce10de4351234018d740e79d47b.