Added fixes to checkpoint writing in analysis

Checkpoint is appended in restart mode and overwritten when opened at
start of calculation with no restart or when analysis is completed.  Most
of this is looked after within OFile now

src/analysis/Analysis.cpp

@@ -156,14 +156,13 @@ old_norm(0.0)
           // Read in data from input file
           readDataFromFile( filename );
           // Setup the restart file (append mode)
-          if( write_chq ) rfile.open( filename.c_str());
+          if( write_chq ) rfile.open( filename.c_str() );  // In append mode automatically because of restart
           // Run the analysis if we stoped in the middle of it last time
           if( idata==ndata ) runAnalysis();
           log.printf("  restarting analysis with %u points read from restart file\n",idata);
       } else if( write_chq ){
           // Setup the restart file (delete any old one)
-          remove( filename.c_str() ); 
-          rfile.open( filename.c_str());
+          rfile.open( filename.c_str() );  // In overwrite mode automatically because there is no restart
       }
       if( write_chq ){
          rfile.addConstantField("old_normalization");
@@ -299,7 +298,6 @@ void Analysis::runAnalysis(){
   // Delete the checkpoint file
   if( write_chq ){
      std::string filename = getName() + "_" + getLabel() + ".chkpnt";
-     if( remove( filename.c_str() )!=0  ) warning("problem deleting checkpoint file " + filename );
      // If we are running more than one calculation only reopen the restart file
      if( !single_run ) rfile.open( filename.c_str(), "w+" ); 
   }