Update the Unicode Data Files license.

COPYING.UCD

+Unicode Data Files include all data files under the directories
+http://www.unicode.org/Public/, http://www.unicode.org/reports/,
+http://www.unicode.org/cldr/data/, http://source.icu-project.org/repos/icu/, and
+http://www.unicode.org/utility/trac/browser/.
+
+Unicode Data Files do not include PDF online code charts under the
+directory http://www.unicode.org/Public/.
+
+Software includes any source code published in the Unicode Standard
+or under the directories
+http://www.unicode.org/Public/, http://www.unicode.org/reports/,
+http://www.unicode.org/cldr/data/, http://source.icu-project.org/repos/icu/, and
+http://www.unicode.org/utility/trac/browser/.
+
+NOTICE TO USER: Carefully read the following legal agreement.
+BY DOWNLOADING, INSTALLING, COPYING OR OTHERWISE USING UNICODE INC.'S
+DATA FILES ("DATA FILES"), AND/OR SOFTWARE ("SOFTWARE"),
+YOU UNEQUIVOCALLY ACCEPT, AND AGREE TO BE BOUND BY, ALL OF THE
+TERMS AND CONDITIONS OF THIS AGREEMENT.
+IF YOU DO NOT AGREE, DO NOT DOWNLOAD, INSTALL, COPY, DISTRIBUTE OR USE
+THE DATA FILES OR SOFTWARE.
+
 COPYRIGHT AND PERMISSION NOTICE
 
-Copyright © 1991-2014 Unicode, Inc. All rights reserved.
-Distributed under the Terms of Use in 
-http://www.unicode.org/copyright.html.
+Copyright © 1991-2018 Unicode, Inc. All rights reserved.
+Distributed under the Terms of Use in http://www.unicode.org/copyright.html.
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of the Unicode data files and any associated documentation
 without restriction, including without limitation the rights to use,
 copy, modify, merge, publish, distribute, and/or sell copies of
 the Data Files or Software, and to permit persons to whom the Data Files
-or Software are furnished to do so, provided that
-(a) this copyright and permission notice appear with all copies 
-of the Data Files or Software,
-(b) this copyright and permission notice appear in associated 
-documentation, and
-(c) there is clear notice in each modified Data File or in the Software
-as well as in the documentation associated with the Data File(s) or
-Software that the data or software has been modified.
+or Software are furnished to do so, provided that either
+(a) this copyright and permission notice appear with all copies
+of the Data Files or Software, or
+(b) this copyright and permission notice appear in associated
+Documentation.
 
 THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF
 ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE