Ability to disable the scheduling for rescan existing nodes when Provisiond starts

The poller/collector servers used on this environment are monitoring different sets of requisitioned nodes on different networks. There are firewalls that prevents each poller/collector server reaching the network monitored by other poller/collector server.

The idea is that each poller/collector server is responsible for the nodes that it is supposed to monitor.

The problem is that when Provisiond starts, it schedules the rescan of all existing nodes on the database. This sounds to be a good thing if we use a single OpenNMS instance. But in this particular environment this doesn't make sense because OpenNMS is going to try to scan all nodes defined on the database on all poller/collector servers.

This is an operation executed when Provisiond starts, so it will be wonderful to define a system property to disable this operation in order to avoid this kind of problems on distributed environments.