unification of persistence and transaction handling for jbpm and human task
added human task jpa module to jbpm distribution

(cherry picked from commit a79a22c528b02dcf929f43e9d43c87849bb236d3)
fixed assembly typo for new module

(cherry picked from commit e7756d561adca4918ec5f9295ff7788be85a9e2f)
added default producer for usergroupcallback and userinfo

(cherry picked from commit 157d479f4c29f6197a6b7b583498bb2854c352e5)
disabled jbpm human task jpa module to avoid new module being added in late stage of the 6.0, will be anabled post 6.0