Tuning heuristics in emap (#639)

* First incomplete tuned emap

* Fixes for tuning estimated references and inverters

* Removing collective references and collective estimations, removing default value initilization for cuts

* Experiment file

* Add new multi-output cut initialization

* Fixes to emap

* Lowering the default memory usage and formatting the code

* Reverting emap experiment to default

* Add updated tests

Author: aletempiac

experiments/emap.cpp

@@ -81,7 +81,7 @@ int main()
     /* remove structural redundancies */
     aig_balancing_params bps;
     bps.minimize_levels = false;
-    bps.fast_mode = false;
+    bps.fast_mode = true;
     aig_balance( aig, bps );
 
     const uint32_t size_before = aig.num_gates();