Remove auto-generated oasis files from repositories

[euanh]

We now have an oasis RPM, which packages can BuildRequire. We should remove all the auto-generated files in our repositories and generate them at build time.

Release tarballs will still need the auto-generated files, so we should also have a script which tags a release and attaches a tarball which includes configure, META, Makefile and so on to the release page on GitHub.