JERSEY-2421: MultiPartFeature requires jersey-server to be on the class-path
JERSEY-2560: NullPointerException on IOException in FormDataParamValueFactoryProvider

 - fix + test

Change-Id: If3a03c814f7bc9c961bc3c6f39cc16285cbeaafe
Signed-off-by: Michal Gajdos <michal.gajdos@oracle.com>