provisioning: associate multiple lines to the same device

[Guigui37]

With some DECT phones, associated to the same base, one MAC address is shared with multiple terminals. So we need a way to associate multiple terminals(users) to the same mac, and use then a loop to create as many account as needed in the provision file associated to the base. This could be usefull too if some people needs more than one account associated to a wired phone.