Simple creation of commands with key-value arguments
Description
The package (which requires e-TeX) provides a natural way to
define commands with optional keys. The package provides
\newkeycommand, \renewkeycommand, \providekeycommand,
\newkeyenvironment and \renewkeyenvironment, together with
\keycmd for a more advanced interface. The package is based on
kvsetkeys by Heiko Oberdiek.