doc: add preprocessor copyright info

preprocessor.tex

@@ -22,7 +22,7 @@
 \usepackage[utf8]{inputenc}
 
 \usepackage{times}
-
+\usepackage[copyright]{ccicons}
 
 \title{The Dynare Preprocessor}
 
@@ -43,6 +43,18 @@
 
 \begin{frame}
   \titlepage
+
+  \begin{columns}[T]
+    \column{0.2\textwidth}
+    \column{0.09\textwidth}
+
+    \ccbysa
+    \column{0.71\textwidth}
+    \tiny
+    Copyright © 2007--2017 Dynare Team \\
+    Licence: \href{http://creativecommons.org/licenses/by-sa/4.0/}{Creative
+      Commons Attribution-ShareAlike 4.0}
+  \end{columns}
 \end{frame}
 
 \begin{frame}