Do Not Disturb mode, tutorial updates and some more

Added Do Not Disturb mode - the customers are now aware of that you're not available and will not leave a negative feedback if you don't answer them as this sign is on your door.

The customer now cannot be dismissed if there's a potion for them and was not given - you will no longer lose it.

Tutorial messages now works somewhat smarter - they pop up one by one and gets dismissed if you do what it suggests.

Added more tooltips for buttons.