ECMAScript target version

[Cantor, Scott]

> We should go for the lowest common denominator in our example (so if
> something will work in rhino and Nashorn that is what we should ship).

Unfortunately those two are fairly different in practice, so beyond simple examples it's common to have to pick one, and I've stuck with Nashorn since that is the official Java implementation now. And given that it will probably be 2021 at the earliest before that changes, it's not an urgent thing to deal with it changing, we just have to keep an eye out.

> Further I think that we need to have the simplest possible code in our
> examples.  So the extra levekl of function indirection that a lot of the samples
> currently have is just confusing for people who are not programmers and
> must want to get a job done.  So we might know that
> 
> (funcrtion(foo, custom, prc){return false;} (input, custom, prc);
> 
> Is the same as
> 
> false;
> 
> but it is far more interesting to our end users that they see the latter.

+1, these are, by and large, already just simple function calls, so that indirection doesn't really add anything useful unless the example is so advanced that there's a portion that needs to be factored. I don't mind an example or two showing it, but they shouldn't routinely.

-- Scott