Fix split lines for Python code

Some characters like Vertical Tab or File Separator were used as line separators.
This is not legal. Line Separators in Python are only Carriage Return \r and Line Feed \n.

test/test_diff_parser.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 from textwrap import dedent
 import logging
 
@@ -952,3 +953,9 @@ def test_wrong_backslash(differ):
     differ.initialize(code1)
     differ.parse(code2, parsers=2, copies=2, expect_error_leaves=True)
     differ.parse(code1, parsers=1, copies=1)
+
+
+def test_random_unicode_characters(differ):
+    differ.initialize('')
+    differ.parse('\x1dĔBϞɛˁşʑ˳˻ȣſéÎ\x90̕ȟòwʘ\x1dĔBϞɛˁşʑ˳˻ȣſéÎ', parsers=1, expect_error_leaves=True)
+    differ.parse('')