- set the default image file extension based on output type

- don't use booktabs on html output
- remove some unused packages


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10980 a1c6a512-1295-4272-9138-f99709370657

manual/preamble.tex

@@ -38,13 +38,13 @@
 \usepackage{graphicx}
 \usepackage{verbatim}
 \usepackage{makeidx}
-\usepackage{amsmath}
-\usepackage{amssymb}
 \usepackage{fancyvrb}
 \usepackage{enumerate}
-\usepackage{subfigure}
 \usepackage{color}
-\usepackage{booktabs}
+\ifpdfoutput{\usepackage{booktabs}}%
+  {\newcommand{%
+    \toprule}{}\newcommand{\midrule}{\hline}\newcommand{\bottomrule}{}%
+  }
 \usepackage{longtable}
 \usepackage{url}
 \urlstyle{sf}
@@ -58,6 +58,12 @@
 %   \draftangle{45}
   }
 
+% pdf output: try pdf first, then png and jpg as file format
+% html output: try png first, then jpg. Ignore pdf files
+% this only applies if no file extension is given!
+\ifpdfoutput{\DeclareGraphicsExtensions{.pdf,.png,.jpg}}%
+    {\DeclareGraphicsExtensions{.png,.jpg}}
+
 % fancy header style adjustments
 \fancyhead{}
 \fancyfoot{}