changed logfile ofstream open from ios::out to ios::app

log.h

@@ -196,7 +196,7 @@ namespace Utilities{
     logfilename = plogfilename;
     
     // setup logfile
-    logfileout.open((dir + "/" + logfilename).c_str(), ios::out);
+    logfileout.open((dir + "/" + logfilename).c_str(), ios::app);
     if(logfileout.bad())
       {
 	throw Exception(string(string("Unable to setup logfile ")+logfilename+string(" in directory ")+dir).c_str());