add Resque_Queue for faster job queuing without baggages related to workers

Since, by definition, we're en-queuing jobs because we want higher requests per second, we should have 
the job en-queuing as light as possible by not wasting time on loading files/functions not needed and cross calling classes. 

In Resque::enqueue, the Job class is loaded which itself load others not needed in this context just for the 
function create which calls back the push method in Resque 

In Resque, functions pop , size, reserve and queue are actually not needed during job queuing. 

I realize that on a high loaded site, enqueuing jobs was slow and loading unecessary files. So I added
a new class just for enqueing jobs fast and this dramatically reduced the cpu load thus gained more rps.