Adding forin examples.
Merge branch 'develop' into forin
Encoding for .. in ..

  - Transformation done in SSA

  for (var k in obj) { <body> }

  ==>

  var _keys = builtin_BIForInKeys(obj); // Array<Imm, { v: string | (keyIn(v,obj) && enumProp(v,obj)) }>
  for (var _i = 0; _i < _keys.length; _i++) {
    var k = _keys[_i];
    <body>
  }
Adding one more example

  - Need to fix forin-01 - subtyping with unions
adding super simple forin-test
Flattening unions after apply

  - XXX: This might not be enough
  - More checks might need to be added
Merge branch 'forin' of github.com:UCSD-PL/RefScript into forin
Fixed tests/pos/forin/forin-000.ts

  - Added extra case in builtin_BIForInKeys
Restoring "not null" on arrays
Scraping qualifs only from specs
Merge pull request #20 from UCSD-PL/forin

Forin