remove control characters from student code output
remove control characters from student code output

EDUlib/xserver,EDUlib/xserver,Marx86/xserver,EDUlib/xserver,edx/xserver,EDUlib/xserver,Marx86/xserver,edx/xserver,edx/xserver,edx/xserver,Marx86/xserver,Marx86/xserver,Marx86/xserver,edx/xserver,EDUlib/xserver