NEW Introduce property module_position so a module can decide where it

dev/skeletons/modMyModule.class.php

htdocs/admin/modules.php

htdocs/core/modules/DolibarrModules.class.php

htdocs/core/modules/modAccounting.class.php

htdocs/core/modules/modAdherent.class.php

htdocs/core/modules/modAgenda.class.php

htdocs/core/modules/modBanque.class.php

htdocs/core/modules/modCashDesk.class.php

htdocs/core/modules/modCommande.class.php

htdocs/core/modules/modComptabilite.class.php

htdocs/core/modules/modDocumentGeneration.class.php

htdocs/core/modules/modECM.class.php

htdocs/core/modules/modExpedition.class.php

htdocs/core/modules/modExpenseReport.class.php

htdocs/core/modules/modFacture.class.php

htdocs/core/modules/modFournisseur.class.php

htdocs/core/modules/modHoliday.class.php

htdocs/core/modules/modMargin.class.php

htdocs/core/modules/modOauth.class.php

htdocs/core/modules/modOpenSurvey.class.php