Adding missing append mode to append_value_to_textfile.

src/level_set/redistancing_Sussman/HelpFunctions.hpp

@@ -75,7 +75,7 @@ bool isApproxEqual(T val1, T val2, T tolerance)
 template <typename T>
 void append_value_to_textfile(std::string & textfile, T value)
 {
-	std::ofstream out(textfile);
+	std::ofstream out(textfile, std::ios_base::app);
 	out << value;
 }