JERSEY-2360: oauth1-client does not really support RSA-SHA1 fully

 - fix
 - added authentication flow test
 - updated documentation

Change-Id: I1dba633cb4fa5af768a246eb04a605e686e70ff4
Signed-off-by: Michal Gajdos <michal.gajdos@oracle.com>
Merge "JERSEY-2360: oauth1-client does not really support RSA-SHA1 fully"