Fix bug with non-ascii reprs inside pretty-printed lists.

Closes gh-597

IPython/core/formatters.py

@@ -433,7 +433,7 b' class PlainTextFormatter(BaseFormatter):'
             # This uses use StringIO, as cStringIO doesn't handle unicode.
             stream = StringIO()
             printer = pretty.RepresentationPrinter(stream, self.verbose,
-                self.max_width, self.newline,
+                self.max_width, self.newline.encode(),
                 singleton_pprinters=self.singleton_printers,
                 type_pprinters=self.type_printers,
                 deferred_pprinters=self.deferred_printers)