Re-added unit test for decoding cookie values
Re-added unit test for decoding cookie values

Whoops. Deleted this from unit tests related to
_getKeyValuePairFromCookieString (since it was no longer a
responsibility of that function) but should have moved it instead, since
the behavior is still important to test.

englishextra/Cookies,ScottHamper/Cookies,ScottHamper/Cookies,englishextra/Cookies