Merge pull request AsyncHttpClient#1135 from elrodro83/public-async-handler

Make HttpTransactionContext#getAsyncHandler public

Author: oleksiys

src/main/java/com/ning/http/client/providers/grizzly/HttpTransactionContext.java

@@ -166,7 +166,7 @@ Connection getConnection() {
         return connection;
     }
 
-    AsyncHandler getAsyncHandler() {
+    public AsyncHandler getAsyncHandler() {
         return future.getAsyncHandler();
     }