Merge from vendor branch TNF:

Merge from vendor branch TNF:
Import tex-etoolbox-2.1 as devel/tex-etoolbox.

The etoolbox package is a toolbox of programming facilities geared
primarily towards LaTeX class and package authors. It provides LaTeX
frontends to some of the new primitives provided by e-TeX as well as
some generic tools which are not strictly related to e-TeX but match the
profile of this package. Note that the initial versions of this package
were released under the name elatex. The package provides functions that
seem to offer alternative ways of implementing some LaTeX kernel
commands; nevertheless, the package will not modify any part of the
LaTeX kernel.