adding jed1.x

I don't actually know that much about Jed format, but this was a quick-and-dirty way to make it work.  I imagine you'll want to clean it up.  There's one thing I'm not sure about, which I commented on below.
Yeah, I was trying to puzzle that out with Jed's unit tests.  Does it seem like they want it to do something more like this? 
```javascript
{
   "domain": "messages",
   "locale_data": {
      "messages": {
         "": {
            "domain": "messages",
            "plural_forms": "nplurals=3; plural=(n==1 ? 0 : n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2);",
            "lang": "pl"
         },
         "Hello, world!\n": [
            "Witaj, świecie!\n"
         ],
         "this is the first line\nthis is the next one\nbut this is the last\n": [
            "to jest pierwsza linia\nto jest następny\nale to jest ostatnia\n"
         ],
         "one product": [
            "jeden produkt"
         ],
         "%d products": [
            "jeden produkt",
            "%d produkty",
            "%d produktów"
         ],
         "A sentence with \"quotation\" marks.": [
            "Zdanie w \"cudzysłowie\"."
         ],
         "string context\u0004the contextual phrase": [
            "zwrot kontekstowe"
         ]
      }
   }
}
```
I may be over thinking it, but do they want a separate key for singular and plural? I'm not sure how it would match on plurals otherwise, since that old first element would be gone in the new Jed format.