Did a couple of adjustment for IP Trunk creation and modification. Added default values for nullable fields.

Changed minimum links to number of members, added a confirmation page for the minimum links value and  made interface description optional.

added import script for reading partners from csv files

create_router workflow takes a router to the PROVISIONING state
subscription service includes method for fetching all PROVISIONING routers
create_iptrunk workflow can now also select PROVISIONING routers next to ACTIVE ones