version 12 by Michael Callaghan
Section 1.11 - Define the door opening capability of the Patroller
OpeningCapability is a kind of value. The OpeningCapabilities are Universal, WithKey, UnlockedOnly and None.
[Universal The Patroller can get through any locked door.
WithKey The Patroller can get through locked doors if s/he holds the matching key.
UnlockedOnly The Patroller can get through unlocked doors only
None The Patroller cannot get through any closed door
Note: Open doors are not treated as a barrier to the Patroller's movement.]
A Patroller has an OpeningCapability. The OpeningCapability of a Patroller is usually None.