Fix obsolete hard-coded cross-references from normal text to list items

Besides avoiding the bad use of hard-coded references, this fixes the problem that the references assume alphabetical enumeration, while the referenced enumeration is numeric.

chapters/functions.tex

@@ -506,11 +506,11 @@ \subsection{Functional Input Arguments}\label{functional-input-arguments-to-func
 %\def\labelenumi{\alph{enumi}.}
 \item\label{functional-argument:type-specifier}
   as a function type-specifier (\lstinline!Parabola! example below),
-\item
+\item\label{functional-argument:partial-application}
   as a function partial application (\cref{function-partial-application} below),
 \item\label{functional-argument:component}
   as a function that is a component (i.e., a formal parameter of function type of the enclosing function),
-\item
+\item\label{functional-argument:component-partial-application}
   as a function partial application of a function that is a component (example in \cref{function-partial-application} below).
 \end{enumerate}
 
@@ -573,7 +573,7 @@ \subsubsection{Function Partial Application}\label{function-partial-application}
 \end{nonnormative}
 
 \begin{example}
-Function partial application as argument, positional argument passing, according to case (b) above:
+Function partial application as argument, positional argument passing, according to case~\ref{functional-argument:partial-application} above:
 \begin{lstlisting}[language=modelica]
 model Test
   parameter Integer N;
@@ -618,7 +618,7 @@ \subsubsection{Function Partial Application}\label{function-partial-application}
 \end{example}
 
 \begin{example}
-Function partial application of a function that is a component, according to case (d) above:
+Function partial application of a function that is a component, according to case~\ref{functional-argument:component-partial-application} above:
 \begin{lstlisting}[language=modelica]
 partial function SurfaceIntegrand
   input Real x;