Stop assuming that all characters except tab and newline are one column wide. [Code that assumes it here](https://github.com/balu/ted/blob/c5373f1b823618738a46098a83cc59d2c6c31779/src/ted.c#L1232) and [here](https://github.com/balu/ted/blob/c5373f1b823618738a46098a83cc59d2c6c31779/src/ted.c#L1441)
