1.Added methods: shower.isSlideMode() & shower.toggleMode(); 2. All with hash and body.classList are incapsulated into shower.enterSlideMode() and shower.enterListMode() (no more copypaste code in eventListener).

1. Add callbacks; 2. Move private methods to the begin of methods list; 3. All JS types starts with Uppercase letter

Add presenter notes support

Check if Shower is already in slide/list mode