loadWithNewGlobal return value has to be properly wrapped

loadWithNewGlobal runs given script in a new 'global' instance. The return result could be a script object -- such an object should be properly wrapped. If not, it will start referring/using objects from caller's "world".

Example:

var glob = loadWithNewGlobal(
  { name: "<code>",
     script: "function func() { return [] }; this;"
  })

// should print false - not an Array of caller's global
print(glob.func() instanceof Array)

// should print false - not an Object from caller's global
print(glob instanceof Object)