Adding the wordpress codebase to the repository

I wanted to avoid having to do this, but I don't see another nice way
for us to generate the patches otherwise.

.gitmodules

+[submodule "app/r2db"]
+	path = app/r2db
+	url = git@git.autistici.org:lucha/r2db

r2db @ 636019a5

+Subproject commit 636019a5fd859f54c1e2fe0db8be181fd185c855