Added the wrap() method for a backpointer

src/main/java/org/kohsuke/github/GHContentWithLicense.java

@@ -14,6 +14,8 @@ class GHContentWithLicense extends GHContent {
     @Override
     GHContentWithLicense wrap(GHRepository owner) {
         super.wrap(owner);
+        if (license!=null)
+            license.wrap(owner.root);
         return this;
     }
 }

src/main/java/org/kohsuke/github/GHLicense.java

@@ -158,4 +158,8 @@ public class GHLicense extends GHObject {
         return url.hashCode();
     }
 
+    /*package*/ GHLicense wrap(GitHub root) {
+        this.root = root;
+        return this;
+    }
 }