Merge pull request #459 from kiwix/opds_category_support

Support for book categories in OPDS feed

Author: kelson42

src/wrapper/java/book.cpp

@@ -69,6 +69,7 @@ GETTER(jstring, getDate)
 GETTER(jstring, getUrl)
 GETTER(jstring, getName)
 GETTER(jstring, getFlavour)
+GETTER(jstring, getCategory)
 GETTER(jstring, getTags)
 GETTER(jlong, getArticleCount)
 GETTER(jlong, getMediaCount)

src/wrapper/java/org/kiwix/kiwixlib/Book.java

@@ -24,6 +24,7 @@ public class Book
   public native String getUrl();
   public native String getName();
   public native String getFlavour();
+  public native String getCategory();
   public native String getTags();
   /**
    * Return the value associated to the tag tagName