Add Testing Automata Product & Emptiness Check

* src/taalgos/stats.hh, src/taalgos/stats.cc: Compute statistics for a
automaton.
* src/ta/ta.hh, src/ta/ta.cc: Abstract representation of a Testing
Automata(TA)
* src/ta/taexplicit.hh, src/ta/taexplicit.cc: Explicit representation of
a Testing Automata (TA)
* src/taalgos/dotty.cc: Print a TA in dot format.
* src/taalgos/reachiter.hh, src/taalgos/reachiter.cc: Iterate over all
reachable states of a TA
* src/taalgos/sba2ta.cc: implements the construction of a TA from a BA
(Buchi Automata)
* src/tgbatest/ltl2tgba.cc: add commands to test the TA implementation
* src/taalgos/emptinessta.hh, src/taalgos/emptinessta.cc: implementation
 of the TA emptiness-check algorithm
* src/ta/taproduct.hh, src/ta/taproduct.cc: representation of the
product (automaton) between a TA and a Kripke structure.
* src/ta/Makefile.am, src/taalgos/Makefile.am: add them

src/ta/Makefile.am

@@ -25,8 +25,11 @@ tadir = $(pkgincludedir)/ta
 
 ta_HEADERS = \
   ta.hh \
+  taproduct.hh \
   taexplicit.hh
-
+  
 noinst_LTLIBRARIES = libta.la
 libta_la_SOURCES = \
+  ta.cc \
+  taproduct.cc \
   taexplicit.cc