Allow boolean atoms to be negated in rational expressions.

* src/ltlparse/ltlparse.yy (rationalexp): Recognize "OP_NOT
booleanatom".
* src/ltlvisit/consterm.cc, src/tgbaalgos/ltl2tgba_fm.cc: Adjust.
* src/tgbatest/ltl2tgba.test: Add one test.

src/ltlvisit/consterm.cc

@@ -76,6 +76,11 @@ namespace spot
 	  switch (uo->op())
 	    {
 	    case unop::Not:
+	      result_ = false;
+	      break;
+	    case unop::Star:
+	      result_ = true;
+	      break;
 	    case unop::X:
 	    case unop::F:
 	    case unop::G:
@@ -84,9 +89,6 @@ namespace spot
 	    case unop::NegClosure:
 	      assert(!"unsupported operator");
 	      break;
-	    case unop::Star:
-	      result_ = true;
-	      break;
 	    }
 	}