ltlcross: add a --products=N option

* src/bin/ltlcross.cc: Implement the new option.  Average the product
statistics on all products.
* src/tgbatest/basimul.test, src/tgbatest/ltlcross.test,
src/tgbatest/ltlcross2.test, bench/ltl2tgba/tools: Use the new option.
* NEWS: Mention it.

src/tgbatest/basimul.test

@@ -54,9 +54,7 @@ ltl2tgba=../../bin/ltl2tgba
 #    --spin -x ba-simul=2
 #    --spin -x ba-simul=3
 
-
-for seed in 1 2 3; do
-  ../../bin/ltlcross --seed=$seed --density=0.$seed \
+../../bin/ltlcross --seed=0 --products=5 --json=out.json \
     -f 'X((F(Xa | b) W c) U (Xc W (a & d)))' \
     -f '((<> p5 V ((p0 U p1) <-> (p5 \/ p1))) -> ((<> p4 V p2) M p2))' \
     -f '!p2 & (Fp5 R (((p0 U p1) & (p5 | p1)) | (!p5 & (!p0 R !p1))))' \
@@ -73,4 +71,3 @@ for seed in 1 2 3; do
     "$ltl2tgba --ba --high --spin -x ba-simul=1 %f >%N" \
     "$ltl2tgba --ba --high --spin -x ba-simul=2 %f >%N" \
     "$ltl2tgba --ba --high --spin -x ba-simul=3 %f >%N"
-done

src/tgbatest/ltlcross.test

@@ -1,6 +1,6 @@
 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2012 Laboratoire de Recherche et
+# Copyright (C) 2012, 2013 Laboratoire de Recherche et
 # Développement de l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
@@ -23,7 +23,7 @@
 ltl2tgba=../ltl2tgba
 
 ../../bin/randltl -n 100 p1 p2 p3 p4 p5 p6 --tree-size 5..15 |
-../../bin/ltlcross \
+../../bin/ltlcross --products=2 \
   "$ltl2tgba -t -l %f > %T" \
   "$ltl2tgba -t -l -R3b -r4 %f > %T" \
   "$ltl2tgba -t -f %f > %T" \
@@ -50,5 +50,3 @@ ltl2tgba=../ltl2tgba
 # Disabled because too slow, and too big automata produced.
 # "$ltl2tgba -t -lo -r4 %f > %T"
 # "$ltl2tgba -t -lo -R3b -r4 %f > %T" \
-
-

src/tgbatest/ltlcross2.test

@@ -23,7 +23,7 @@
 ltl2tgba=../../bin/ltl2tgba
 
 ../../bin/randltl -P -n 100 p1 p2 p3 p4 p5 p6 --tree-size 5..15 |
-../../bin/ltlcross \
+../../bin/ltlcross --products=3 \
 "$ltl2tgba --lbtt --any --low %f > %T" \
 "$ltl2tgba --lbtt --any --medium %f > %T" \
 "$ltl2tgba --lbtt --any --high %f > %T" \