DW      VECT            ; Draw line from (X1,Y1) to (X2,Y2)

  Input:
     AX         X1; The beginning X coordinate for the line
     BX         Y1; The beginning Y coordinate for the line
     CX         X2; The ending X coordinate for the line
     DX         Y2; The ending Y coordinate for the line

  Return:
     Nothing

Draws a line from the (X1,Y1) to (X2,Y2). The current LINESTYLE setting is
used to draw the line. Note: CP is NOT changed by this vector.