[IO-616] Add class AppendableWriter. #87.

Author: Gary Gregory

src/changes/changes.xml

@@ -122,6 +122,9 @@ The <action> type attribute can be add,update,fix,remove.
       <action issue="IO-615" dev="ggregory" type="add" due-to="Gary Gregory, Rob Spoor">
         Add classes TeeWriter, FilterCollectionWriter, ProxyCollectionWriter, IOExceptionList, IOIndexedException.
       </action>
+      <action issue="IO-616" dev="ggregory" type="add" due-to="Rob Spoor">
+        Add class AppendableWriter. #87.
+      </action>
     </release>
 
     <release version="2.6" date="2017-10-15" description="Java 7 required, Java 9 supported.">