Update to latest CC-BY 4.x license text

Copied from https://creativecommons.org/licenses/by/4.0/legalcode.txt

LICENSE

@@ -33,7 +33,7 @@ exhaustive, and do not form part of our licenses.
      material not subject to the license. This includes other CC-
      licensed material, or material used under an exception or
      limitation to copyright. More considerations for licensors:
-	wiki.creativecommons.org/Considerations_for_licensors
+    wiki.creativecommons.org/Considerations_for_licensors
 
      Considerations for the public: By using one of our public
      licenses, a licensor grants the public permission to use the
@@ -48,9 +48,9 @@ exhaustive, and do not form part of our licenses.
      rights in the material. A licensor may make special requests,
      such as asking that all changes be marked or described.
      Although not required by our licenses, you are encouraged to
-     respect those requests where reasonable. More_considerations
-     for the public: 
-	wiki.creativecommons.org/Considerations_for_licensees
+     respect those requests where reasonable. More considerations
+     for the public:
+    wiki.creativecommons.org/Considerations_for_licensees
 
 =======================================================================
 
@@ -378,7 +378,7 @@ Section 8 -- Interpretation.
 Creative Commons is not a party to its public
 licenses. Notwithstanding, Creative Commons may elect to apply one of
 its public licenses to material it publishes and in those instances
-will be considered the "Licensor." The text of the Creative Commons
+will be considered the “Licensor.” The text of the Creative Commons
 public licenses is dedicated to the public domain under the CC0 Public
 Domain Dedication. Except for the limited purpose of indicating that
 material is shared under a Creative Commons public license or as
@@ -393,3 +393,4 @@ the avoidance of doubt, this paragraph does not form part of the
 public licenses.
 
 Creative Commons may be contacted at creativecommons.org.
+