Format the given block of text, trimming leading/trailing
    empty lines and any leading whitespace that is common to all lines.
    The purpose is to let us list a code block as a multiline,
    triple-quoted Python string, taking care of
    indentation concerns.
    http://code.activestate.com/recipes/145672/

def format_block(block, nlspaces=0):
    """
    Format the given block of text, trimming leading/trailing
    empty lines and any leading whitespace that is common to all lines.
    The purpose is to let us list a code block as a multiline,
    triple-quoted Python string, taking care of
    indentation concerns.
    http://code.activestate.com/recipes/145672/
    """
    # separate block into lines
    lines = smart_text(block).split('\n')

    # remove leading/trailing empty lines
    while lines and not lines[0]:
        del lines[0]
    while lines and not lines[-1]:
        del lines[-1]

    # look at first line to see how much indentation to trim
    ws = re.match(r'\s*', lines[0]).group(0)
    if ws:
        lines = map(lambda x: x.replace(ws, '', 1), lines)

    # remove leading/trailing blank lines (after leading ws removal)
    # we do this again in case there were pure-whitespace lines
    while lines and not lines[0]:
        del lines[0]
    while lines and not lines[-1]:
        del lines[-1]

    # account for user-specified leading spaces
    flines = ['%s%s' % (' ' * nlspaces, line) for line in lines]

    return '\n'.join(flines) + '\n'