bin: introduce autcross

Fixes #252.

* NEWS: Mention it.
* bin/autcross.cc, bin/man/autcross.x, doc/org/autcross.org: New
files.
* bin/Makefile.am, bin/man/Makefile.am, doc/org/tools.org,
doc/Makefile.am: Add them.
* bin/autfilt.cc: Use is_universal() instead of is_deterministic().
* bin/common_hoaread.hh, bin/common_trans.cc, bin/common_trans.hh,
bin/ltlcross.cc, bin/ltldo.cc: Factor some bits common between
ltlcross, ltldo and autcross.
* tests/core/autcross.test, tests/core/autcross2.test: New files.
* tests/Makefile.am: Add them.
* tests/core/dra2dba.test, tests/core/sbacc.test,
tests/core/streett.test: Use autcross.

tests/core/sbacc.test

@@ -163,7 +163,7 @@ test 4 = `ltl2tgba -S 'F(a & X(!a &Xb))' --any --stats=%s`
 
 # Test case from Thibaud Michaud.  This used to fail, because sbacc()
 # would remove acceptance marks from all rejecting SCCS...
-cat >tm.hoa <<EOF
+autcross 'autfilt --sbacc' --language-preserve <<EOF
 HOA: v1
 States: 5
 Start: 1
@@ -188,8 +188,6 @@ State: 4
 [!2] 3 {1}
 --END--
 EOF
-autfilt --sbacc tm.hoa > out.hoa
-autfilt -q --equivalent-to out.hoa tm.hoa
 
 # Tautological acceptances are converted to "t"
 cat >taut.hoa <<EOF