Fix for date serialization problem in JsonRequestProcessor. Datanucleus returns custom subtypes of java.util.Date from the datastore, which causes Dates to be serialized as english strings.

Review at http://gwt-code-reviews.appspot.com/790801


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@8619 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/requestfactory/server/JsonRequestProcessor.java b/user/src/com/google/gwt/requestfactory/server/JsonRequestProcessor.java
index 564a3d1..a0974cf 100644
--- a/user/src/com/google/gwt/requestfactory/server/JsonRequestProcessor.java
+++ b/user/src/com/google/gwt/requestfactory/server/JsonRequestProcessor.java
@@ -320,7 +320,7 @@
     if (Boolean.class == type) {
       return value;
     }
-    if (Date.class == type) {
+    if (Date.class.isAssignableFrom(type)) {
       return String.valueOf(((Date) value).getTime());
     }
     if (Enum.class.isAssignableFrom(type)) {