fix for persistence, improved initialization of org and domains
 - updating installer
- ExternalTaskEventListener - removing system outs for the second time
- moving task assignment initialization to TaskServiceEntryPointImpl
- reverting un needed changes in PersistenceManagerImpl
- reverting back changes for initialization of the persistence mechanism
Removed SequenceGenerator because it does not work in OpenJPA
Removed SequenceGenerators because they are not allowed when using id
generation type AUTO
Revert "Removed SequenceGenerator because it does not work in OpenJPA"

This reverts commit f83f36d8663772e5b102cb6004c59679380239c0.
FIX: Type "org.jbpm.task.impl.model.EmailNotificationImpl" uses a flat
inheritance mapping, but declares a table name of "EmailNotification",
which does not match the superclass table "Notification".
FIX: You have supplied columns for ... but this mapping cannot have
columns in this context.
FIX: No metadata was found for type "class
org.jbpm.task.impl.model.DeadlinesImpl"
FIX: (more) You have supplied columns for ... but this mapping cannot
have
columns in this context.
Replace "in elements" with "member of" in named queries
Replaced Collections.emptyList() with new ArrayList() because OpenJPA
does not know how to handle Collections.emptyList()
Only create user if it does not exist in the database
Use the return value of addTask as taskId. The taskId in task might not
get updated.
Use the return value of addTask as taskId. The taskId in task might not
get updated.
Replaced "in elements" with JPA conform "member of"
Replaced "= null" with JPA conform "is null"
Replaced "status in" with "... or ...". openJPA can not handle Enum
Strings in queries.