[plt-scheme] handler:edit-file in Windows

> >     (handler:edit-file (send a-definitions-text get-filename))
>
> Are the two filenames "spelled" identically?

They seem to be.  I assume the definitions text returns the same
filename each time I ask for it, but DrScheme opens an additional tab
each time I call handler:edit-file, resulting in an arbitrary number
of tabs for the same file.

Greg