This returns a copy of the screen as a unicode string. This is similar to
        __str__/__unicode__ except that lines are not terminated with line
        feeds.

def dump (self):
        '''This returns a copy of the screen as a unicode string. This is similar to
        __str__/__unicode__ except that lines are not terminated with line
        feeds.'''

        return u''.join ([ u''.join(c) for c in self.w ])