Adding some hibernate validator
Hibernate Validator

CHANGELOG:
- ComputerValidator and DateValidator converted to Contraints
- Adding a finalize in ConnectionManager (maybe it will fix outofmem)
- Adding annotations in dto and models
Fix : edit works again (select name changed)
Create a checkPage constraint

CHANGELOG:
- @CheckPage checks if currentPage and pageLimit are correct
- Add custom message on ComputerDto annotation
clean groupesequence on ComputerDto
internationalization 1st part (missing errors messages)