Use CBSD task to run the deferred task for updating bhyve PID after launching.
This is the work-around for Issue #399
in fact, we need a separated daemon as a bhyve monitor for monitoring
bhyve process or /dev/vmm/ entry via kqueue.
I added fast work-around for updating PID via 'cbsd task' ( you can see this task via 'cbsd taskls' ) - added special args for bset ( cbsd bset vm_pid=auto );
I plan to rewrite 'cbsdd' to beanstalkd-based broker sooner or later. It will solve some problems with
big amount of internal CBSD tasks (or multi-task).