fixed detection of secure cookies received over https

BrowserKit's cookie handling only recognises a secure cookie if the
cookie option is set and the cookie was set over an https request.
The client was not passing the url into the cookiejar update code,
causing Cookie::isSecure() to always return false for every cookie.

Fixes symfony/symfony#7666
[BrowserKit] removed dead code
[HttpFoundation][BrowserKit] fixed path when converting a cookie to a string

An empty path has a different meaning than a /; it means that the path
is the one from the current URI.
Merge branch '2.1' into 2.2

* 2.1:
  [HttpFoundation][BrowserKit] fixed path when converting a cookie to a string
  [BrowserKit] removed dead code
  [HttpFoundation] fixed empty domain= in Cookie::__toString()
  fixed detection of secure cookies received over https
  [Translation] removed an uneeded class property
  [Translation] removed unneeded getter/setter
  [Translator] added additional conversion for encodings other than utf-8
  fix a DI circular reference recognition bug
  [HttpFoundation] fixed the creation of sub-requests under some circumstances for IIS
Merge branch '2.2'

* 2.2:
  [Config] #7644 add tests for passing number looking attributes as strings
  [HttpFoundation][BrowserKit] fixed path when converting a cookie to a string
  [BrowserKit] removed dead code
  [HttpFoundation] fixed empty domain= in Cookie::__toString()
  fixed detection of secure cookies received over https
  [2.2] Pass ESI header to subrequests
  [Translation] removed an uneeded class property
  [Translation] removed unneeded getter/setter
  [Translator] added additional conversion for encodings other than utf-8
  fixed source messages to accept pluralized messages [Validator][translation][japanese] add messages for new validator
  fix a DI circular reference recognition bug
  [HttpFoundation] fixed the creation of sub-requests under some circumstances for IIS

Conflicts:
	src/Symfony/Component/HttpFoundation/Tests/CookieTest.php
fixed Client implementation to return the right Response (closes #4475)
alternate fix where we had accessor for the BrowerKit request/response instances
made some small tweaks