Modified entire test directory to suit new GPU constructs for looping

tests/forces/Test_rect_force.cc

@@ -89,7 +89,7 @@ int main (int argc, char ** argv)
     auto Uprime_v = Uprime.View();
     auto U_v      = U.View();
     auto mom_v    = mom.View();
-    thread_loop( (auto i=mom_v.begin();i<mom_v.end();i++),{ // exp(pmu dt) * Umu
+    thread_foreach(i,mom_v,{ // exp(pmu dt) * Umu
       Uprime_v[i](mu) = U_v[i](mu) + mom_v[i](mu)*U_v[i](mu)*dt ;
     });
   }