Switch to dot access of properties in Facilities.

I’ve noticed that quick help doesn’t work for the automatically
synthesized variables (_propertyname). Apple recommends that you use
dot access or accessor methods outside of initialization,
deallocation, or custom accessor methods. See
https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/EncapsulatingData/EncapsulatingData.html#//apple_ref/doc/uid/TP40011210-CH5-SW6
section “Most Properties Are Backed by Instance Variables”. I won't
change the other files yet.
Implement Coat Check from facilities.