Some improvements to size scripts

- Added -L/--depth argument to show dependencies for scripts/stack.py,
  this replaces calls.py
- Additional internal restructuring to avoid repeated code
- Removed incorrect diff percentage when there is no actual size
- Consistent percentage rendering in test.py

scripts/test.py

@@ -803,9 +803,9 @@ def main(**args):
             failure.case.test(failure=failure, **args)
             sys.exit(0)
 
-    print('tests passed %d/%d (%.2f%%)' % (passed, total,
+    print('tests passed %d/%d (%.1f%%)' % (passed, total,
         100*(passed/total if total else 1.0)))
-    print('tests failed %d/%d (%.2f%%)' % (failed, total,
+    print('tests failed %d/%d (%.1f%%)' % (failed, total,
         100*(failed/total if total else 1.0)))
     return 1 if failed > 0 else 0