[Positioning] OutputTerminal: handle flush-output-files

Flush the output stream when the option flush-output-files is activated.

owlps-positioning/src/outputterminal.cc

@@ -1,5 +1,6 @@
 #include "outputterminal.hh"
 #include "resultlist.hh"
+#include "configuration.hh"
 
 
 
@@ -16,4 +17,6 @@ void OutputTerminal::write(const ResultList &results)
     output_stream << "There is no result.\n" ;
   else
     output_stream << results << '\n' ;
+  if (Configuration::bool_value("flush-output-files"))
+    output_stream << std::flush ;
 }