* src/bin/common_output.hh, src/bin/common_output.cc: Fix includes.

src/bin/common_output.cc

@@ -21,6 +21,7 @@
 
 #include "common_output.hh"
 #include <iostream>
+#include "ltlvisit/tostring.hh"
 
 #define OPT_SPOT 1
 

src/bin/common_output.hh

@@ -27,7 +27,7 @@
 #endif
 
 #include <argp.h>
-#include "ltlvisit/tostring.hh"
+#include "ltlast/formula.hh"
 
 enum output_format_t { spot_output, spin_output, utf8_output };
 extern output_format_t output_format;