code refactoring for adding support to multiple "comics views"

two "comics views" added, classic (flow+table_view) and grid (based on qml/qtquick)
TODO: the views are only interchangeable in compilation time, some more work is needed for doing it in run time.
fixed reloadCovers

YACReaderLibrary/yacreader_local_server.cpp

@@ -64,7 +64,12 @@ bool YACReaderLocalServer::isRunning()
 	socket.connectToServer(YACREADERLIBRARY_GUID);
 	if (socket.waitForConnected(500)) 
 		return true; // Server is running (another instance of YACReaderLibrary has been launched)
-	return false;
+    return false;
+}
+
+void YACReaderLocalServer::close()
+{
+    localServer->close();
 }