These are extended versions of X's DrawString primitives which
allow tabs to be in the strings.

I'd eventually like to see all the FWF widgets have XfwfString's with
both the font change capabilities of Motif strings, and these tabbing
capabilities.  Right now, the tabbing capability has been added to
only the Label widget and the MultiList widget, and there is no
concept of font changes.

-Rick Richardson (rick@digibd.com)
