Add automation interface for blurbit

[larryhastings]

Mariatta needs a utility function for her blurb-on-the-web project. The function should be something like:

def format_blurb_filename(section, bpo_no, body, date=None)

and it should return the filename relative to the Python root.

[Mariatta]

Thanks Larry, so actually I will need the filename returned with out the slash in front.
So just Misc/News.d/.....