rename some variables and begin compiled sim c code

sim/compiled_sim.c

@@ -0,0 +1,7 @@
+
+void sim_init(int num_gates, int num_nets);
+void sim_add_gate();
+void sim_add_net();
+void sim_tick();
+void sim_get_net_state(int objref);
+void sim_get_port_state(int objref, int index);