Changes:

- Add a new cache to store library covers without relying on Glide's cache, making sure they are always available.
- Use Observable's defer instead of create in NetworkHelper.
- Fix Kissmanga showing only one genre.

app/src/main/java/eu/kanade/mangafeed/ui/library/LibraryHolder.java

@@ -4,12 +4,8 @@ import android.view.View;
 import android.widget.ImageView;
 import android.widget.TextView;
 
-import com.bumptech.glide.Glide;
-import com.bumptech.glide.load.engine.DiskCacheStrategy;
-
-import java.util.Objects;
-
 import eu.kanade.mangafeed.R;
+import eu.kanade.mangafeed.data.cache.CoverCache;
 import eu.kanade.mangafeed.data.database.models.Manga;
 import uk.co.ribot.easyadapter.ItemViewHolder;
 import uk.co.ribot.easyadapter.PositionInfo;
@@ -43,17 +39,11 @@ public class LibraryHolder extends ItemViewHolder<Manga> {
             unreadText.setVisibility(View.GONE);
         }
 
-        String thumbnail;
-        if (manga.thumbnail_url != null)
-            thumbnail = manga.thumbnail_url;
-        else
-            thumbnail = "http://img1.wikia.nocookie.net/__cb20090524204255/starwars/images/thumb/1/1a/R2d2.jpg/400px-R2d2.jpg";
-
-        Glide.with(getContext())
-                .load(thumbnail)
-                .diskCacheStrategy(DiskCacheStrategy.RESULT)
-                .centerCrop()
-                .into(this.thumbnail);
+        if (manga.thumbnail_url != null) {
+            CoverCache.loadLocalInto(getContext(), thumbnail, manga.thumbnail_url);
+        } else {
+            thumbnail.setImageResource(android.R.color.transparent);
+        }
     }
 
 }