Class skeletons

Resolves https://github.com/KSHSK/WAVED/issues/86 https://github.com/KSHSK/WAVED/issues/87 https://github.com/KSHSK/WAVED/issues/88 https://github.com/KSHSK/WAVED/issues/89 https://github.com/KSHSK/WAVED/issues/90 https://github.com/KSHSK/WAVED/issues/91