:return: A list with the paths which are stored in a text file in a line-by-
             line format. Validate each path using is_valid_path

def path_file_to_list(path_file):
    """
    :return: A list with the paths which are stored in a text file in a line-by-
             line format. Validate each path using is_valid_path
    """
    paths = []
    path_file_fd = file(path_file)

    for line_no, line in enumerate(path_file_fd.readlines(), start=1):
        line = line.strip()

        if not line:
            # Blank line support
            continue

        if line.startswith('#'):
            # Comment support
            continue

        try:
            is_valid_path(line)
            paths.append(line)
        except ValueError, ve:
            args = (ve, path_file, line_no)
            raise ValueError('%s error found in %s:%s.' % args)

    return paths