Add side tab widget icons

- Add config to prioritize icon only if it has one

src/DockAreaTitleBar.cpp

@@ -120,6 +120,15 @@ struct DockAreaTitleBarPrivate
 		return CDockManager::testConfigFlag(Flag);
 	}
 
+	/**
+	 * Returns true if the given config flag is set
+	 * Convenience function to ease config flag testing
+	 */
+	static bool testConfigFlag(CDockManager::eOverlayFlag Flag)
+	{
+		return CDockManager::testConfigFlag(Flag);
+	}
+
 	/**
 	 * Test function for current drag state
 	 */