re-add the dreaded button to offline

org.fox.ttrss/src/main/java/org/fox/ttrss/offline/OfflineActivity.java

@@ -465,6 +465,20 @@ public class OfflineActivity extends CommonActivity {
 				refresh();
 			}
 			return true;
+		case R.id.toggle_unread:
+			if (oap != null) {
+				int articleId = oap.getSelectedArticleId();
+
+				SQLiteStatement stmt = getDatabase().compileStatement(
+						"UPDATE articles SET modified = 1, unread = NOT unread WHERE "
+								+ BaseColumns._ID + " = ?");
+				stmt.bindLong(1, articleId);
+				stmt.execute();
+				stmt.close();
+
+				refresh();
+			}
+			return true;
 		/* case R.id.selection_select_none:
 			deselectAllArticles();			
 			return true; */
@@ -596,6 +610,9 @@ public class OfflineActivity extends CommonActivity {
 					m_menu.findItem(R.id.toggle_published).setIcon(published ? R.drawable.ic_checkbox_marked :
 						R.drawable.ic_rss_box);
 
+					m_menu.findItem(R.id.toggle_unread).setIcon(unread ? R.drawable.ic_email :
+							R.drawable.ic_email_open);
+
 					article.close();
 				}				
 			}

org.fox.ttrss/src/main/res/menu/activity_offline.xml

@@ -53,11 +53,11 @@
             android:icon="@drawable/ic_rss_box"
             app:showAsAction="ifRoom"
             android:title="@string/article_toggle_published"/>
-        <!-- <item
+        <item
             android:id="@+id/toggle_unread"
             android:icon="@drawable/ic_email"
             app:showAsAction="ifRoom"
-            android:title="@string/article_toggle_unread"/> -->
+            android:title="@string/article_toggle_unread"/>
         <!-- <item
             android:id="@+id/share_article"
             android:icon="@drawable/ic_share"