\funcitem{}, \dataitem{}, \excitem{}: Removed obsolete macros; there are no

\funcitem{}, \dataitem{}, \excitem{}:  Removed obsolete macros; there are no
	longer used anywhere.  Use the {*desc} environments instead.

\var{}:  Ensure that the argument is always set in roman italic, in case an
	 alternate font is being used for code.  These keeps the result of
	 \var{} consistent.

Some minor changes to allow easier exploration of alternate fonts for code in
the running text.  Haven't changed the selected font; I haven't found one that
has everything required!  (The best non-monospaced font so far was missing
the <, >, and | characters, or at least had them at the wrong locations.  It
also allowed confusion between upper-case I and lower-case L.)