Initial skeleton
Add ipaddresses file and collections definition plus index
Add AddressState
Skeleton AddIPAddress
Minor fixes
Skeleton implementation of IPAddress
Initial implementation of Remove
Updated comments for methods
Implementation of SetState
Extend Subnet.Remove to also remove IP addresses
Comment update
Change AddIPAddress to take network.Address and subnet id
Remove unneeded IPAddressInfo
Skeleton test
Test extension
New test
Test extension
Test extension
Failing test for SetState
Test passes