json: relax the parser some more

Allow bare strings with all non-special other chars.
Add # to comment a line till \n
Allow = as separator for keys
Fix end of string handling.

Now:

 {
   "#": "this is a comment"
   "key": "value",
   "foo": 24
 }

and

  {
    # this is a comment
    key = value
    foo = 24
  }

Parse to the same thing with less clutter.