Fix for #114: unneccesary newline printed every time a "direct call" made.

Fix for #114: unneccesary newline printed every time a "direct call" made.

My fix for #84 (cfec4f1ed81a8e733effbaa93acd917e7f6bded0) neglected to
take into account the fact that interpret() would be called before the
game ends under certain rare circumstances. Therefore, I've added a
reset_screen() to main() which contains the final call to new_line().