JDF-782: Replace add-user instructions and fix links to point to JBoss ddeveloper shared repository

@rafabene : In addition to the link, can you please make sure the credentials specified are also correct? 

@mareknovotny : I modified the create admin user as you suggested.
Shouldn't the right one be : EAP_HOME/bin/add-user.sh -a -u 'quickstartUser' -p 'quickstartPwd1!' -g 'guest' ?