Always show worker count

In some instances, we've seen resqued process families with fewer workers than the configuration called for. This branch changes the procline to expose the parent's internal state.

    resqued-0.7.9 listener 86 [70f726d] [running] [1/2/3 workers] config/resqued.rb

In the procline, `1/2/3` refers to "1 worker in my immediate process family", "I know of two workers in the larger process family that are running queues I know about", and "3 total workers are configured".

While the processes are starting or stopping, the procline may be inaccurate.