When gforth starts up, there is a bare "string.fs" in included-files. Looking at the source, it seems to be hard-coded in. This means that if I have my own string.fs and try to `require` it, nothing happens, which is bad.
On a similar note, on the Windows build, *all* of the filenames in included-files are bare filenames with no absolute path, so this could happen with quite a lot of common names... --Josh
