Fixed loading of external numeration modules in Contrat, Commande, Facture, Contrat, Expedition, Fichinter, CommandeFournisseur and uniformized code

Conflicts:
	htdocs/compta/prelevement/class/bonprelevement.class.php

withdrawals.

Conflicts:
	ChangeLog

withdrawals.

$soc already filled upper if $socid filled

$soc already filled upper when $socid send

and cost price, or by external module)

for release.

Use lowest buying price for margin when selling with POS or external
module. A POS user does not worry about suppliers.