Disables the code for fetching SVN-revision info.
Obviously, this is because we have emigrated to github.
Merge pull request #72 from Carn/ShowRevision

Disables the code for fetching SVN-revision info until we can get a Git equivalent working. According to carn var/global/datum/getrev/revdata may be useful to us in the future so it can stay for now. Resolves Issue #65