Making EPERM friendlier

The problem that's being addressed here is that a well written application that is going to tell the user what went wrong only knows that permisison was denied.

The application cannot provide any more information to the user, because it doesn't have the information.

And there is no sane way for the admin/support person to figure out _why_ the permission was denied.

In the 'old days', this was fairly simple, there was only one place to check (the rwx permissions).

However today, it's much harder.

When you don't give admins sane ways to figure out the cause of the permission problems within the context of the more complex security model, the result is going to be that admins disable the more complex security model, a secure system that doesn't get the job done is worthless.