HMC bit repro across checkpoints. Fixed parallel RNG issue with threading.

Conclusion: c++11 distributions not thread safe and must us distinct dist as well as distinct engine
per site. Makes sense when you think of box muller. Also added a reset of dist on fill to ensure
repro across checkpoints.

lib/qcd/hmc/integrators/Integrator.h

@@ -165,7 +165,6 @@ namespace Grid{
 	    H += Hterm;
 	  }
 	}
-	std::cout<<GridLogMessage << "Total action H = "<< H << "\n";
 	
 	return H;
       }