Update entrepot.class.php

bad element name
Update entrepot.class.php
Update main.inc.php
Update mouvementstock.class.php

return mouvement id instead simply "1", i need to store the movement id on my factory modules (to update it at the end of the build process if it's need)
replace mvid by $mvid, wrong week-end
Merge pull request #1679 from defrance69/patch-1

Update entrepot.class.php