Configuration support to allow for stashing of restrictions more aggressively

Currently, when a job is moved from a queue to its corresponding restriction queue a work-cycle is lost. This change adds functionality that uses/respects the environment variable: "GET_QUEUED_JOB_RETRIES" to control the maximum number of iterations to do while looking for "queued" work (this is also the maximum number of queued jobs that will be moved to the restriction queue per invocation of "get_queued_job"). With this change, in its current state, the default functionality is the same.

Functionally, I think this change seems sound, however I am having some difficulty using tests to verify, please see the stubbed tests in the pull request.