Mapping between old Tcl and Tk versions.

archives/7/7.0/tk     ->../../3/3.3
archives/7/7.1/tk     -> ../../3/3.4
archives/7/7.3/tk     -> ../../3/3.6
archives/7/7.4/tk     -> ../../4/4.0
archives/7/7.5/p1/tk  -> ../../../4/4.1/p1
archives/7/7.5/tk     -> ../../4/4.1
archives/7/7.6/p2/4.2 -> ../../../4/4.2/p2
archives/7/7.6/tk     -> ../../4/4.2