Add missing generics markup and remove suppress warnings annotation

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1631962 13f79535-47bb-0310-9956-ffa450edef68
Improve filterByDate(Timestamp) to not filter by date when the passed in Timestamp is null.  Better mimics the behavior of EntityUtil.filterByDate(Timestamp)

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1631963 13f79535-47bb-0310-9956-ffa450edef68