usage: cvt [-v|--verbose] [-r|--reduced] X Y [refresh]

 -v|--verbose : Warn about CVT standard adherence.
 -r|--reduced : Create a mode with reduced blanking (default: normal blanking).
            X : Desired horizontal resolution (multiple of 8, required).
            Y : Desired vertical resolution (required).
      refresh : Desired refresh rate (default: 60.0Hz).

Calculates VESA CVT (Coordinated Video Timing) modelines for use with X.