Could someone please review patch 799428: fix Tkinter tk_focusNext?

[Russell E. Owen]

Patch <http://bugs.python.org/issue799428> is a trivial (one word) fix 
to a long-standing issue with Tkinter: calls to the widget method 
tk_focusNext() fail with "unsubscriptable object" error.

Admittedly we've lived a long time with this bug. But the fix is so 
simple and so obviously safe that it seems a shame to leave it out.

it would be especially nice to get this into the first Python 2.6 
release so one could assume the fix is present if using any flavor of 
2.6 or newer.

This fix is truly trivial: it just wraps a return from tk in str() to 
avoid the problem of getting an object back in less-than-ancient 
versions of tcl/tk.

-- Russell