Tests for case-senstivity were not being skipped for darwin when installed on a
case-sensitive filesystems -- which is not the default case. Along the way also
fixed the skipping of tests when sys.dont_write_bytecode is true.

Closes issue #5442 again.
diff --git a/Misc/NEWS b/Misc/NEWS
index 537434b..c531f1e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -19,6 +19,15 @@
   now it does.  This also means getfp method now returns the real fp.
 
 
+Tests
+-----
+
+- Issue 5442: Tests for importlib were not properly skipping case-sensitivity
+  tests on darwin even when the OS was installed on a case-sensitive
+  filesystem. Also fixed tests that should not be run when
+  sys.dont_write_bytecode is true.
+
+
 What's New in Python 3.1 beta 1?
 ================================