Initial support for sources' login. Upgrade support library version.

app/src/main/java/eu/kanade/mangafeed/sources/Batoto.java

@@ -98,6 +98,11 @@ public class Batoto extends Source {
         return SourceManager.BATOTO;
     }
 
+    @Override
+    public boolean isLoginRequired() {
+        return true;
+    }
+
     @Override
     protected String getUrlFromPageNumber(int page) {
         return INITIAL_UPDATE_URL + page;

app/src/main/java/eu/kanade/mangafeed/sources/Source.java

@@ -33,6 +33,11 @@ public abstract class Source {
     protected abstract List<String> parseHtmlToPageUrls(String unparsedHtml);
     protected abstract String parseHtmlToImageUrl(String unparsedHtml);
 
+    // True if the source requires a login
+    public boolean isLoginRequired() {
+        return false;
+    }
+
     // Get the URL to the details of a manga, useful if the source provides some kind of API or fast calls
     protected String getMangaUrl(String defaultMangaUrl) {
         return defaultMangaUrl;