Move non-normative motivation for package to start of chapter,

and move up most definitions as discussed.

chapters/packages.tex

@@ -1,13 +1,5 @@
 \chapter{Packages}\label{packages}
-
-\section{Package as Specialized Class}\label{package-as-specialized-class}
-
-The package concept is a specialized class (\cref{specialized-classes}), using the
-keyword \lstinline!package!.
-
-\section{Motivation and Usage of Packages}\label{motivation-and-usage-of-packages}
-
-\begin{nonnormative}
+\label{motivation-and-usage-of-packages}
 Packages in Modelica may contain definitions of constants and
 classes including all kinds of specialized classes, functions, and
 subpackages. By the term subpackage we mean that the package is declared
@@ -40,9 +32,12 @@ \section{Motivation and Usage of Packages}\label{motivation-and-usage-of-package
   standard mapping of package names to storage places, typically file or
   directory locations in the file system.
 \end{itemize}
-\end{nonnormative}
+\section{Package as Specialized Class}\label{package-as-specialized-class}
+
+The package concept is a specialized class (\cref{specialized-classes}), using the
+keyword \lstinline!package!.
 
-\subsection{Importing Definitions from a Package}\label{importing-definitions-from-a-package}
+\section{Importing Definitions from a Package}\label{importing-definitions-from-a-package}
 
 The import-clause makes public classes and other public definitions
 declared in some package available for use by shorter names in a class
@@ -85,7 +80,7 @@ \subsection{Importing Definitions from a Package}\label{importing-definitions-fr
 Here $\mathit{packagename}$ is the fully qualified name of the imported package including possible dot notation and $\mathit{definitionname}$ is the name of an element in a package.  The multiple definition import is equivalent
 to multiple single definition imports with corresponding $\mathit{packagename}$ and definition names.
 
-\subsubsection{Lookup of Imported Names}\label{lookup-of-imported-names}
+\subsection{Lookup of Imported Names}\label{lookup-of-imported-names}
 
 This section only defines how the imported name is looked up in the import clause. For lookup in general -- including how import clauses are used -- see \cref{static-name-lookup}.
 
@@ -114,7 +109,7 @@ \subsubsection{Lookup of Imported Names}\label{lookup-of-imported-names}
 \end{lstlisting}
 \end{nonnormative}
 
-\subsubsection{Summary of Rules for Import Clauses}\label{summary-of-rules-for-import-clauses}
+\subsection{Summary of Rules for Import Clauses}\label{summary-of-rules-for-import-clauses}
 
 The following rules apply to import-clauses:
 \begin{itemize}
@@ -137,7 +132,7 @@ \subsubsection{Summary of Rules for Import Clauses}\label{summary-of-rules-for-i
   Multiple qualified import-clauses may not have the same import name.
 \end{itemize}
 
-\subsection{Mapping Package/Class Structures to a Hierarchical File System}\label{mapping-package-class-structures-to-a-hierarchical-file-system}
+\section{Mapping Package/Class Structures to a Hierarchical File System}\label{mapping-package-class-structures-to-a-hierarchical-file-system}
 
 Packages/classes may be represented in the hierarchical structure of the
 operating system (the file system). For classes with version
@@ -162,7 +157,7 @@ \subsection{Mapping Package/Class Structures to a Hierarchical File System}\labe
 Tools may also store classes in data-base systems, but that is not standardized.
 \end{nonnormative}
 
-\subsubsection{Mapping a Package/Class Hierarchy into a Directory Hierarchy (Structured Entity)}\label{mapping-a-package-class-hierarchy-into-a-directory-hierarchy-structured-entity}
+\subsection{Mapping a Package/Class Hierarchy into a Directory Hierarchy (Structured Entity)}\label{mapping-a-package-class-hierarchy-into-a-directory-hierarchy-structured-entity}
 
 A directory shall contain a node, the file \filename{package.mo}. The node shall contain a stored-definition that defines a class \lstinline!A! with a name
 matching the name of the structured entity.
@@ -195,7 +190,7 @@ \subsubsection{Mapping a Package/Class Hierarchy into a Directory Hierarchy (Str
 \filename{package.mo} (this ensures that the relative order between classes and
 constants stored in different ways is preserved).
 
-\subsubsection{Mapping a Package/Class Hierarchy into a Single File (Nonstructured Entity)}\label{mapping-a-package-class-hierarchy-into-a-single-file-nonstructured-entity}
+\subsection{Mapping a Package/Class Hierarchy into a Single File (Nonstructured Entity)}\label{mapping-a-package-class-hierarchy-into-a-single-file-nonstructured-entity}
 
 When mapping a package or class-hierarchy to a file (e.g.\ the file \filename{A.mo}), that file shall only define a single class \lstinline!A! with a
 name matching the name of the nonstructured entity. In a file hierarchy the files shall have the extension \filename{.mo}.
@@ -204,7 +199,7 @@ \subsubsection{Mapping a Package/Class Hierarchy into a Single File (Nonstructur
 to file-structure and it is an error if it is loaded from the
 \lstinline!MODELICAPATH!.
 
-\subsubsection{The within Clause}\label{the-within-clause}
+\subsection{The within Clause}\label{the-within-clause}
 
 A within-clause has the following syntax:
 \begin{lstlisting}[language=grammar]
@@ -230,7 +225,7 @@ \subsubsection{The within Clause}\label{the-within-clause}
 \end{lstlisting}
 \end{example}
 
-\subsection{External resources}\label{external-resources}
+\section{External resources}\label{external-resources}
 
 In order to reference external resources from documentation (such as
 links and images in html-text) and/or to reference images in the Bitmap
@@ -285,7 +280,7 @@ \subsection{External resources}\label{external-resources}
 resource than \filename{modelica://Modelica/C.jpg}.
 \end{example}
 
-\subsection{The Modelica Library Path -- MODELICAPATH}\label{the-modelica-library-path-modelicapath}
+\section{The Modelica Library Path -- MODELICAPATH}\label{the-modelica-library-path-modelicapath}
 
 The top-level scope implicitly contains a number of classes stored
 externally. If a top-level name is not found at global scope, a Modelica
@@ -314,7 +309,7 @@ \subsection{The Modelica Library Path -- MODELICAPATH}\label{the-modelica-librar
 fails without searching for \lstinline!A! in any of the remaining roots in \lstinline!MODELICAPATH!.
 \end{nonnormative}
 
-\subsubsection{Example of Searching MODELICAPATH}\label{example-of-searching-modelicapath}
+\subsection{Example of Searching MODELICAPATH}\label{example-of-searching-modelicapath}
 
 If during lookup a top-level name is not found in the unnamed top-level
 scope, the search continues in the package hierarchies stored in these