Do controlled shutdown when cxy_ctl:remove_task_types is called

[jaynel]

Currently remove_task_types deletes a necessary record from the cxy_ctl table and eliminates the ets ring buffer used to record execution timing. Either of these changes can cause a running process which attempts to execute a task to crash with badarg or worse.

Instead, this function should set the Max Active Procs to 0 and wait for all spawns and inline procs to stop before deleting anything from the ets table.