Shortcut module's access checking is insane

The access control handler duplicates the procedural code in shortcut.module (or vice versa, of course). The access check logic itself is also very, very bizarre: shortcut access checking checks if the associated shortcut set exists, for example, but that's nonsensical, because a shortcut cannot exist without a shortcut set.

In short: clean up shortcut module's access checking. It'll be much simpler and less error-prone.

Beta phase evaluation