'Required:
nothing
Returns
nothing (changes value of self.__system_string)
Logic:
iterate through the system string, and match arguments with options:
old_list = [\'--foo\', \'bar\']
new_list = [\'--foo=bar\''

def __pair_arg_with_option(self):

    opt_len = len(self.__system_string)
    new_system_string = []
    counter = 0
    slurp_value = 0
    for arg in self.__system_string:
        counter += 1
        if slurp_value:
            slurp_value = 0
            continue
        if (arg[0] != '-'):
            new_system_string.append(arg)
        elif ('=' in arg):
            new_system_string.append(arg)
        elif (arg in self.__opt_with_args):
            if ((counter + 1) > opt_len):
                sys.stderr.write(('option    "%s"    must    take    an    argument\n' % arg))
                new_system_string.append(arg)
                self.__options_okay = 0
            elif (self.__system_string[counter][0] == '-'):
                sys.stderr.write(('option    "%s"    must    take    an    argument\n' % arg))
                new_system_string.append(arg)
                self.__options_okay = 0
            else:
                new_system_string.append(((arg + '=') + self.__system_string[counter]))
                slurp_value = 1
        else:
            new_system_string.append(arg)
    return new_system_string
