start to pull out allocator from core model
separating out allocator code - to decouple them..
fix all tests
towards policies using spec directly
complete re-factoring of allocator to operate on specs only -
more tidyup of the allocator tests
start to decouple host_repository from the stacks model.
fix up actions to send specs through to the allocator.
missing some tests here that we need to put in..
refactoring to encapsulate the allocator and not leak its internals as
much.
more refactoring of allocator to aid encapsulation.
clean up services not directly exposed anymore
tidying up
more tidying up.
remove cname task, as it is defunct
include ephemeral allocator and basic dns service