Log config on startup

[ZimbiX]

Inspired by some of @benhoskings's commits on Ferocia's fork.

Startup now looks like:

➜ ./bin/que ./app.rb                                                                                                     
Que started worker process with:
  Worker threads: 6 (priorities: 10, 30, 50, any, any, any)
  Buffer size: 2-8
  Queues:
    - default (poll interval: 5s)
Que waiting for jobs...

➜ ./bin/que -w 9 -p 1,2,3,4,5,6,7 -i 1.2 -q a=10 -q b=20.05 -q c --minimum-buffer-size 0 --maximum-buffer-size 1 ./app.rb
Que started worker process with:
  Worker threads: 9 (priorities: 1, 2, 3, 4, 5, 6, 7, any, any)
  Buffer size: 0-1
  Queues:
    - a (poll interval: 10.0s)
    - b (poll interval: 20.05s)
    - c (poll interval: 1.2s)
Que waiting for jobs...

[oeoeaio]

Nice one!