Allow implicit self in escaping closures when self is explicitly captured

[Jumhyn (Frederick Kellison-Linn)]

For those interested in this pitch, I have an implementation which addresses the first two of @dabrahams's suggestions above, but does not incorporate this one:

@dabrahams

Close an existing hole in the reference cycle protection provided by this rule (pointed out by John Harper), by adding the rule that an escaping bound method or property of a class requires “ self. ” qualification:

After my initial investigation work I hit a wall and have been unable to dedicate the time and effort necessary to adequately address this issue. The question I faced is summarized here for anyone that feels strongly about ensuring that this feature be included in the proposal, but absent some additional assistance I will likely have to move forward with the proposal excluding this aspect.