Should clear any terminal output when done

[gavinwahl]

Before sdb exits, it should [optionally?] clear all of its output from the terminal.

This function can be used:

def clearlines(n=1):
    """
    Clear the past n lines from the terminal

    http://ascii-table.com/ansi-escape-sequences-vt-100.php
    """
    sys.stdout.write("\033[%sA" % n)  # move cursor up n lines
    sys.stdout.write("\033[J")  # clear screen from cursor down

It works in xterm and urxvt, at least.