Reform eventual send syntax

[erights]

bob ! foo(carol)

is an eventual send using the proposed infix bang syntactic sugar. It needs to expand to something. For present purposes, we also need to write out code without sugar. The expansion currently supported by this repository

Vow.resolve(bob).e.foo(carol)

serves neither of these purposes well. For manually written code, I suggest

E(bob).foo(carol)

where E is equivalent to

function E(target) { return Vow.resolve(target).e; }

[erights]

The danger leaving in support for either .e. or E(...) is that the exposed proxy may be reified rather than immediately invoked. If we continue to use either of these, we probably want to give ourselves a linting rule to catch this easy error.