Cleanup lib/ironic

This moves around a bunch of functionality and attempts to isolate setup
steps into discrete functions (new or existing), making them easier to
consume from outside of Devstack (ie, Grenade).

Change-Id: I480167dcc008506ec2fe8c412db4114b74496e60
diff --git a/lib/nova_plugins/hypervisor-ironic b/lib/nova_plugins/hypervisor-ironic
index c068c74..344ef04 100644
--- a/lib/nova_plugins/hypervisor-ironic
+++ b/lib/nova_plugins/hypervisor-ironic
@@ -56,6 +56,9 @@
 
 # install_nova_hypervisor() - Install external components
 function install_nova_hypervisor {
+    if ! is_service_enabled neutron; then
+        die $LINENO "Neutron should be enabled for usage of the Ironic Nova driver."
+    fi
     install_libvirt
 }