Added examples for File and Timer.

#include <iostream>

#include <TNL/File.h>

#include <TNL/String.h>

using namespace TNL;

using namespace std;

int main()

{

    File file;

    file.open( String("new-file.tnl"), IOMode::write );

    String title("Header");

    file.write( title );

    file.close();

    file.open( String("new-file.tnl"), IOMode::read );

    String title2;

    file.read( title2, 4);

    file.close();

    if fileExists( "new-file.tnl" )

         std::remove( "new-file.tnl" );

}

#include <iostream>

#include <TNL/Timer.h>

using namespace TNL;

using namespace std;

int main()

{

    Timer time;

    time.start();

    time.stop();

    time.getRealTime();

    time.reset();

}