fix regression with cookiejar.iteritems()
preserve python2-like dict API for RequestCookieJar
split cookiejar as dict test
Re-raise DecodeError
Merge pull request #1816 from daftshady/master

Re-raise DecodeError
Merge pull request #1807 from podshumok/fix-request-cookiejar-as-dict

cookiejar.iteritems() is broken after 2.1.0 update