Use inet_ntop
[lib/nfv] selftest.sh: Added timeout to `wait_vm_up'.
[core.app/core.lib] Moved `equal' from `core.app' to `core.lib'.
[unified conf] Replace all uses of `dofile' and `loadstring' with the
central `core.lib.load_conf' and `core.lib.load_string'.

Provide central `lib.load_conf' and `lib.store_conf' to read and write
config files and use `store_conf' to generate zone configurations in
`designs/neutron/neutron2snabb'.

Replace leftover string app args with table literals.
Merge pull request #309 from eugeneia/lib/nfv/selftest-timeout

[lib/nfv] selftest.sh: Added timeout to `wait_vm_up'.
Merge pull request #303 from dpino/fix-ntop

Use inet_ntop
Merge pull request #310 from eugeneia/unify-config

Unify NFV and app configuration
[lib.nfv] selftest.sh: Use the same Snabb instance and VMs to run all
tests.
[designs/neutron/snabbnfv-traffic] Check for new config every second.