Make figs includable in main document

Remove the capability to build them as standalone document but we can
include them in the main document.  It should simplify things down the
road.

book/figures/fig-process-flat-bread.tex

@@ -1,6 +1,3 @@
-\input{./vars}
-
-\begin{document}
 \begin{tikzpicture}[node distance = 3cm, auto, every node/.style={inner sep=10, outer sep=0}]
 \node [block] (init) {Mix ingredients};
   \node [block, right of=init, node distance=5cm] (wait) {Wait for dough to be ready};
@@ -8,4 +5,3 @@
   \path [line] (init) -- (wait);
   \path [line] (wait) -- (bake_bread);
 \end{tikzpicture}
-\end{document}