This does not really have many user-facing changes. The one big change
is that users now should initialize plugins in the
NetControl::init()
event instead of bro_init.
Once all plugins finished initializing and the NetControl framework
starts operations, the NetControl::init_done() event is raised.
Rules that are sent to NetControl before the plugins have finished
initializing are ignored - this is important when several plugins that
require external connections have to be initialized at the beginning.
Without this delay, rules could end up at the wrong plugin.