Switch to side-by-side view

--- a/src/main.cxx
+++ b/src/main.cxx
@@ -294,6 +294,9 @@
         if (g_config->get("pkgdatadir", g_datadir)) {
             path_catslash(g_datadir);
             iconpath = path_cat(g_datadir, "icon.png");
+            if (!path_exists(iconpath)) {
+                iconpath.clear();
+            }
             presentationhtml = path_cat(g_datadir, "presentation.html");
         }
         g_config->get("iconpath", iconpath);