fixing bug #5478
implementing NodeDetail#clone instead of cloning object in apps
using orderNumber when getting nodes by level
ney bug #5478 :   Merge branch 'ney-bug-5478' of https://github.com/NicolasEYSSERIC/Silverpeas-Core into master
ney bug #5478 :   Fix the test NodeDAOTest#testGetHeadersByLevel coming from the correction of the bug