Fixed appendix image alignment.

docs/data/diagrams.tex

@@ -262,6 +262,7 @@
 \newcommand{\eventpropagationfigure}{
     \begin{figure}[h!]
         \center
+        \vspace{-2em}
         \subfigure[An event is triggered in the white area. The event is first
         delegated to the white area from te gray area (2). After gesture
         detection, it is propagated back to the gray area (6) \emph{unless}