Please cherry-pick:

Please cherry-pick:
- removed explicit flush() on entity manager as this hurts performance + may
  cause trouble when other entities (concurrently) are not "ready to be flushed)
- implemented addBranchOffice() + added missing public constructor
- added private method isBranchOfficeFound() which uses the general EJB for
  retrieving whole branch office list
- added protected getManaged() for Contact and Country instances
- renamed companyDataId -> basicDataId

Signed-off-by: Roland Häder <roland@mxchange.org>