Return entire module as promise

[buu700]

As discussed in #105.

[jedisct1]

Awesome!

[buu700]

Oh, sorry, just noticed I forgot to remove line 565 (thought I'd done that before committing).

[jedisct1]

No problem. Removed :)

[jedisct1]

Aie. It doesn't seem to work, at least without wasm.

> require('libsodium-wrappers')

{ add: [Function],
  base64_variants:
   { ORIGINAL: 1,
     ORIGINAL_NO_PADDING: 3,
     URLSAFE: 5,
     URLSAFE_NO_PADDING: 7 },
  compare: [Function],
  from_base64: [Function],
  from_hex: [Function],
  from_string: [Function: a],
  increment: [Function],
  is_zero: [Function] }

Not a promise :(

[jedisct1]

And with wasm, the promise is rejected

ReferenceError: libsodiumModule is not defined

[jedisct1]

Don't bother if this looks hard to fix, we can stick to the previous system with the promise returned along with other properties.

[jedisct1]

00e8ed0 probably fixes the second thing :)

[jedisct1]

Now without wasm we get all the symbols. But directly, instead of the promise.

[buu700]

Oops, sorry about the libsodiumModule oversight. Not exactly sure why it would return everything directly in the non-wasm case, but #109 might fix that.