Sleep for a random amount of time between 5 and 300 seconds when work cannot be found.
Let the work method in "lib/resque/worker.rb" take care of setting the default sleep-interval
Change "lib/resque/tasks.rb" back to its default implementation
Add the default value for "interval" back to the "work" method. Also, always generate a random sleep-time between "interval" and 300 seconds
Externalize configuration of "{min,max}_interval" -- used by: "work" method, default to: "interval" value
Add conversion, validation, and normalization for "interval"
Merge branch 'staggered_sleep'