Added CHANGELOG for #78

Author: weierophinney

CHANGELOG.md

@@ -24,6 +24,11 @@ All notable changes to this project will be documented in this file, in reverse
 - [#45](https://github.com/zendframework/zend-mail/pull/45) ensures that the
   message parser allows deserializing message bodies containing multiple EOL
   sequences.
+- [#78](https://github.com/zendframework/zend-mail/pull/78) fixes the logic of
+  `HeaderWrap::canBeEncoded()` to ensure it returns correctly for header lines
+  containing at least one multibyte character, and particularly when that
+  character falls at specific locations (per a
+  [reported bug at php.net](https://bugs.php.net/bug.php?id=53891)).
 
 ## 2.6.1 - 2016-02-24