$dateSelector is a paramters of formAddObjectLine, if use global it is
reset to 0 because not declare in outer context but already exists in
the same context.
Merge branch '3.6' of git@github.com:Dolibarr/dolibarr.git into 3.6
Fix Ajax combobox in Extrafeilds
Add Extrafield on contract
restore min jquery
Merge pull request #1711 from FHenry/3.6_contractextrafields

3.6 contractextrafields