Added a test for PositionalAccuracy constants.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK8@1627748 13f79535-47bb-0310-9956-ffa450edef68
Merge from the JDK8 branch.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK7@1627892 13f79535-47bb-0310-9956-ffa450edef68