[libvirt] [PATCH 2/2] hacking: add a section on preprocessor conventions

[Jim Meyering]

Eric Blake wrote:
> * doc/hacking.html.in (preprocessor): New section to document
> recently-discussed style issues.
>
> This patch assumes that we are willing to mass-update preprocessor
> indentation via Jim's cppi tool.

Thanks for writing that.
Obviously I would not object.
Daniel Veillard ok'd it, too, so I've pushed it.