Created foreign key relations for llx_product and llx_product_price table
Removed key restrictions
Merge branch 'db-relations' of github.com:marcosgdf/dolibarr into
marcosgdf-db-relations

Conflicts:
	htdocs/install/mysql/migration/3.6.0-3.7.0.sql
Merge branch 'marcosgdf-db-relations' into develop