fix two issues related to jupyter notebook execution

* tests/python/ipnbdoctest.py: Invert diffs inputs.
* tests/run.in: Run notebooks with
PYTHONIOENCODING=utf-8:surrogateescape to avoid exceptions when trying
to display utf-8 characters on ascii terminals.

tests/python/ipnbdoctest.py

@@ -285,7 +285,7 @@ def test_notebook(ipynb):
             print("output length mismatch (expected {}, got {})".format(
                   len(cell.outputs), len(outs)))
             failed = True
-        if not compare_outputs(outs, cell.outputs):
+        if not compare_outputs(cell.outputs, outs):
             failed = True
         print("cell %d: " % i, end="")
         if failed: