More accurate return type in MetadataStandard.getInterface/getImplementation(...) methods,
and added a trivial Characters.isHexadecimal(int) method to be needed later for a JSON parser.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK8@1617481 13f79535-47bb-0310-9956-ffa450edef68
Updates for GeoAPI changes (review upgrade to ISO 19115:2014).


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK8@1617580 13f79535-47bb-0310-9956-ffa450edef68
Merge from the JDK8 branch.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK7@1617582 13f79535-47bb-0310-9956-ffa450edef68
Merge from the JDK7 branch.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK6@1617584 13f79535-47bb-0310-9956-ffa450edef68