Cleanup the runtime mess
Try to make a proposition to cleanup the runtime interface.
Based on what @reazulhoque needs for PaRSEC DTD, the need to fix the flushes, and the need to move to asynchronous acquire callbacks. I suggest we clean up the RUNTIME interface to do that.
Here is a proposition of interface, that does not include the profiling and the options yet.
I'm waiting for feedbacks from @all