[merge][1.0] force docutils to accept --pack-0.92 as an option

[Alexander Belchenko]

Martin Pool пишет:
> Ian pointed out that docutils was not correctly parsing this option text:
> 
>   Branch Format:
>     --pack-0.92         New in 0.92: Pack-based format with data
> compatible with dirstate-tags format
>                         repositories. Interoperates with bzr
> repositories before 0.92 but cannot be
> 
> This is a crude patch to work around it; I'll submit a diff to the
> upstream author in the hope it can be fixed properly.
> 
> 
bb:approve (because BB said APPROVE is not valid vote :-P)