Rewriting improved gnats converter

[Daniel Berlin]

On Sat, 12 Apr 2003, J. Paul Reed wrote:

> On 12 Apr 2003 at 20:12:15, Daniel Berlin moved bits on my disk to say:
>
> > String concatenation speed difference.
>
> Please 'splain.

The re's run roughly the same speed in either language.
Besides the re's, the time is bounded by the time it takes
to add lines to multiline fields.
The python version is faster at this.