#4768: store base64 encoded email body parts as text, not binary.

Patch and tests by Forest Bond.
diff --git a/Misc/NEWS b/Misc/NEWS
index 9195a04..0dff231 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -398,6 +398,9 @@
 Library
 -------
 
+- Issue #4768: base64 encoded email body parts were incorrectly stored as
+  binary strings.  They are now correctly converted to strings.
+
 - Issue #8833: tarfile created hard link entries with a size field != 0 by
   mistake.