test starting all examples

test_startup.sh

@@ -30,5 +30,8 @@ check() {
 error=0
 check main.py || error=1
 check examples.py || error=1
-check examples/slideshow/main.py || error=1
+for path in examples/*
+do
+    check $path/main.py || error=1
+done
 test $error -eq 0