Rename job_queue_add() as job_queue_push() and job_queue_dequeue() as job_queue_pop()

While nonstandard naming is nonideal, it is not worth renaming things for the sake of renaming and breaking dependent code. This renaming can take place if the arguments to job_queue_add() are completely rearranged.

HI drumm,

Stack has push and pop operation not queue. queue and stack both are different. queue has inqueue and dequeue operation.