(- fix) `runInNewContext.client()` was failing on Internet Explorer

Turns out, Internet Explorer won't expose `.contentWindow` on new `<iframe>`s until *after* they've
been added to the DOM.

(cherry picked from commit e5152eb)
(- fix meta doc) Noting an odd Testling failure
(new meta) Adding a .gitlabels file, describing our labels
(new api) Implemented `sub.withAliens()`

This supplements `sub.withAccessors()` on Internet Explorer 6, and in other environments without
`__proto__` accessors. It has definite downsides, explored in the commentary in the source-code.
(fix) A Function's `_runtimeBody` member was being ignored

In `Function` subclasses, the `_runtimeBody` member is intended to supercede the encoded
`runtimeBody` applied at subclass-time, if it exists.
(meta new api incomplete) Preforming meta-project set-up.

I've added a `package.json` for NPM, and set up some tasks for Grunt.js.

I'm preparing the project for a time when I'll be providing a prepared “distribution” file to be
included into the web-client (I have every intention of providing a [Bower][] component for
`from()`).

Finally, I started adding Grunt integration specifically for running the various test combinations;
but, unfortunately, there's no `grunt-testling`; and calling out to the shell by hand is
excruciatingly difficult in Node / Grunt. I can't be arsed, so I'll wait either for a
`grunt-testling`, or at least for `grunt-exec` to be updated for Grunt 0.4.0a.

  [Bower]: <http://twitter.github.com/bower/> "The Browser Package Manager"
(- fix tests) Testling (node-tap, really) doesn't yet support `notStrictEqual()`.
(- new doc) Cleaning up the intro a bit, for docco output.
(- re api) `subclass()` is a much more descriptive name
(- new plumbing API) `subclass()` can now pass `arguments` intact

Although passing `this` and each of the arguments on to an internal function (via a pattern like
`fn.apply(this, arguments)`) is usually sufficient, ocassionally one also wants access to something
more (for instance, `arguments.callee` or `arguments.callee.caller`). By passing `true` as the last
argument to `subclass()`, you can now have the `arguments` object passed wholesale to the inner
function (the one used as the `runtimeBody`.

This is most effective if you name the only argument to the inner function, itself, as `arguments`
(although I'm not sure how widely supported an argument named `arguments` might be, since that's
theoretically overriding the `arguments` object itself):

    var inner = function(arguments){
       // ... do something with `arguments.caller`
    }
    subclass(Function, Something, inner, true)
(- meta new fix) Cleaning up my .gitlabels
(re new) Splitting the file into *three* nested sub-enclosures.

I'm using the same approach I used for the plubing, to move the low-level API down below the
high-level API, even though the latter depends upon the former. Weird, I know; but I believe it
increases readability (and more importantly, skimability) of the literary-code enough to make it
worthwhile.
(- fix) With the new nested enclosures, delayed-assignment not necessary
+ returning a `new From` as the “root”
+ normalizing new-invoked function call style
+ sketching out `new From`