Certain servers may not set a whitespace after colon (in Set-Cookie), causing a PHP notice to be thrown.
* Added two incomplete, but valid "Set-Cookie:" and "Set-Cookie: " headers to the test dataprovider
* Modified behaviour of SetCookie::getFieldValue() in case of empty header
Merge branch 'fix-setcookie-without-space-after-colon' of git://github.com/vmattila/zf2 into hotfix/3699
Merge branch 'hotfix/3699'

Close #3699