Show file path in the repository

With `helm-ff-transformer-show-only-basename` set to `t`, helm-cmd-t only displays a file's base name but not its path in the repository. This is annoying for a repository that has multiple files that have the same name.

However, `(set helm-ff-transformer-show-only-basename t)` makes `helm-find-files` too verbose.

I haven't checked other CVS, but at least `git --no-pager ls-files --full-name` returns a list of relative paths. Couldn't we simply ignore `helm-ff-transformer-show-only-basename`?