chriso/validator.js — pull request #284 by tgfjt (2014-05-08 03:44:43+00:00)
Title: support Surrogate Pair #isLength

`validator.isLength('𠀋一郎', 1, 3)` get `false`,
but I think that its 3 letters, and I want to get `true`.

This is the case of using surrogate pairs.
> `'𠀋'.length;` // return 2.