At one point, Tk::TextUndo supported the four following features:
	<F5> indent selected text block
	<F6> unindent selected text block
	<F7> comment selected text block
	<F8> uncomment selected text block

They were included as undocumented and unsupported features.

The user could select a block of text, and by pressing <F5>
every line selected would be prefixed with a tab at the
start of the line.

Somewhere along the line, these features stopped working.

This tarball includes a recent version of Tk::TextUndo
where the above features are working properly again.