Broke the User-Contract relationship
/!\ Warning: web-app projects at this points do NOT compile!!! /!\
Refactored TanaguruOrchestrator so that it takes Act and user mail as
inputs and returns the same act with its audit filled and its status
updated. This way, it doesn't have to care about current user or whoever
launched/created the Act, and the ACL rights can be cleanly handled in
the caller (AuditLauncherController).

ACLs right not yet managed, but TODO's show where code about that have
to be.
Deleted unsued factory class (impl is created as a bean by Spring)
Changed comparison of user Id for an actual use of ACLs in
#isUserAllowedToDisplaySetUpPage .
Changed #isAdmin to support user with multiple roles.