Update jquery.cookie.js from 1.1 to 1.4.1.

The child of #1476.

- jquery.cookie. from 1.1 (Jul 2012) to 1.4.1 (Apr 2014). Changelog is here: https://github.com/carhartl/jquery-cookie/blob/master/CHANGELOG.md. Quick research showed that we don't rely on these changes but still it'd be better to make this update thoroughly.
  - 1.4.0. `$.cookie('name')` now returns `undefined` in case such cookie does not exist (was `null`). Because the return value is still falsy, testing for existence of a cookie like `if ( $.cookie('foo') )` keeps working without change.
  - 1.4.0. Badly encoded cookies no longer throw exception upon reading but do return `undefined` (similar to how we handle JSON parse errors with `json = true`).
  - 1.4.0. Dropped `$.cookie('name', null)`. Replaced with `$.removeCookie('name')`.