Closes #2252

Specify how to deal with lib/dll on Windows.

chapters/functions.tex

@@ -2173,7 +2173,10 @@ \subsection{Annotations for External Libraries and Include Files}\doublelabel{an
 The "win32"/"win64" directories may contain "gcc47", "vs2010", "vs2012"
 for specific versions of these compilers and these are used instead of
 the general "win32"/"win64" directories, and similarly for other
-platforms.
+platforms. 
+
+The library on Windows may refer to a lib-file (static library), both a lib- and dll-file (in this case the lib-file is an import-library), 
+or just a dll-file.
 
 If the directory for the specific compiler version is missing the
 platform specific directory is used. {[}\emph{A tool may give