clarify license, as confirmed by Ian Bicking

LICENSE.txt

@@ -0,0 +1,7 @@
+Copyright (c) 2005-2012 Ian Bicking, Richard Cyganiak
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -6,7 +6,8 @@ htmldiff outputs HTML that shows the differences in text between
 two versions of an HTML document. Differences in markup are not
 shown.
 
-Original version is from [Ian Bicking](https://github.com/ianb).
+Original version is from [Ian Bicking](https://github.com/ianb)
+with changes from [Richard Cyganiak](https://github.com/cygri).
 
 ## Requirements
 
@@ -39,3 +40,7 @@ this slightly better, at the price of less speed and more noise.
 * Allow diffing only of a given section by specifying an `id`
 * Allow input by URL
 * Make a web service
+
+## License
+
+MIT License, see `LICENSE.txt`.