Linux compatible stopwatch fixes (to_string abandoned)

src/ITAStopWatch.cpp

@@ -163,14 +163,17 @@ double ITAStopWatch::selftest()
 
 std::string TimeToString( double dTimeSeconds)
 {
-	if (dTimeSeconds < 1e-6)
-		return std::string(std::to_string( long double( dTimeSeconds / 1e-9) ) + "us");
+	std::stringstream ss;
+	if( dTimeSeconds < 1e-6 )
+		ss << dTimeSeconds / 1e-9 << "us";
 	else if (dTimeSeconds < 1e-3)
-		return std::string(std::to_string( long double( dTimeSeconds / 1e-6)) + "ns");
+		ss << dTimeSeconds / 1e-6 << "ns";
 	else if (dTimeSeconds < 1e-0)
-		return std::string(std::to_string( long double( dTimeSeconds / 1e-3)) + "ms");
+		ss << dTimeSeconds / 1e-3 << "ms";
 	else
-		return std::string(std::to_string( long double( dTimeSeconds)) + "s");
+		ss << dTimeSeconds << "s";
+
+	return ss.str();
 };
 
 std::string ITAStopWatch::ToString() const