Optimize Java string serialization.  Patch from Evan Jones.
diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index 6c002af..7fe99ec 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -80,6 +80,8 @@
     * Fixes for Solaris 10 32/64-bit confusion.
   Evan Jones <evanj@mit.edu>
     * Optimize Java serialization code when writing a small message to a stream.
+    * Optimize Java serialization of strings so that UTF-8 encoding happens only
+      once per string per serialization call.
     * Clean up some Java warnings.
   Michael Kucharski <m.kucharski@gmail.com>
     * Added CodedInputStream.getTotalBytesRead().