expkv is a minimalistic but fast and expandable <key>=<val>
implementation. It provides two parsing macros:
\ekvset{<set>}{<key=val list>} which is comparable to keyval's
\setkeys. \ekvparse<cs1><cs2>{<key=val list>} which can be used
inside \expanded and expands to <cs1>{key} and <cs2>{key}{val}
for the entries in the <key=val list>. expkv has predictable
brace-stripping behaviour and handles commas and equal signs
with category codes 12 and 13 correctly. A key-defining
interface that is not as rudimentary as the macros provided in
this package is contained in expkv-def.
