Make MD_RestrictionCode tolerant to both "license" and "licence" spelling.
The former was used in ISO 19115:2003 while the later is used in ISO 19115:2014.
XML document shall continue to use the "license" spelling for now, until ISO/OGC
publish the new XML schemas.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK8@1609862 13f79535-47bb-0310-9956-ffa450edef68