AXIOM-311: Refactored testDefaultAttributeType.

git-svn-id: https://svn.apache.org/repos/asf/webservices/axiom/trunk@1592900 13f79535-47bb-0310-9956-ffa450edef68
Added an item to the Axiom 1.3 roadmap.

git-svn-id: https://svn.apache.org/repos/asf/webservices/axiom/trunk@1592901 13f79535-47bb-0310-9956-ffa450edef68
Consolidated the addAttribute test cases.

git-svn-id: https://svn.apache.org/repos/asf/webservices/axiom/trunk@1592902 13f79535-47bb-0310-9956-ffa450edef68