mealy: make output_assignment the default for reduce_mealy

* spot/twaalgos/mealy_machine.hh: Here. Also cite the FORTE paper.
* doc/spot.bib (renkin.22.forte): New entry.

doc/spot.bib

@@ -214,13 +214,13 @@
   doi		= {10.1109/DepCoS-RELCOMEX.2009.31}
 }
 
-@InProceedings{	cimatti.06.fmcad,
-  author	= {Cimatti, Alessandro and Roveri, Marco and Semprini, Simone and
-		  Tonetta, Stefano},
-  title	= {From {PSL} to {NBA}: a Modular Symbolic Encoding},
-  booktitle	= {Proceedings of the 6th conference on Formal Methods in Computer
-		  Aided Design (FMCAD'06)},
-  pages	= {125--133},
+@InProceedings{	  cimatti.06.fmcad,
+  author	= {Cimatti, Alessandro and Roveri, Marco and Semprini, Simone
+		  and Tonetta, Stefano},
+  title		= {From {PSL} to {NBA}: a Modular Symbolic Encoding},
+  booktitle	= {Proceedings of the 6th conference on Formal Methods in
+		  Computer Aided Design (FMCAD'06)},
+  pages		= {125--133},
   year		= {2006},
   publisher	= {IEEE Computer Society},
   doi		= {10.1109/FMCAD.2006.19}
@@ -858,6 +858,22 @@
   doi		= {10.1007/978-3-030-59152-6_7}
 }
 
+@InProceedings{	  renkin.22.forte,
+  author	= {Florian Renkin and Philipp Schlehuber-Caissier and
+		  Alexandre Duret-Lutz and Adrien Pommellet},
+  title		= {Effective Reductions of {M}ealy Machines},
+  year		= 2022,
+  booktitle	= {Proceedings of the 42nd International Conference on Formal
+		  Techniques for Distributed Objects, Components, and Systems
+		  (FORTE'22)},
+  series	= {Lecture Notes in Computer Science},
+  volume	= 13273,
+  pages		= {170--187},
+  month		= jun,
+  publisher	= {Springer},
+  doi		= {10.1007/978-3-031-08679-3_8}
+}
+
 @InProceedings{	  rozier.07.spin,
   author	= {Kristin Y. Rozier and Moshe Y. Vardi},
   title		= {LTL Satisfiability Checking},