[Zope] RDF Summary to support also newsforge RSS

[Heimo Laukkanen]

I had a problem with RDFSummary showing Newsforge's feeds. I got runtime 
error until I added the tags described below to the RDFSummary.py-code.

# Additions for newsforge
   'http://slashcode.com/rss/1.0/modules/Slash/ slash': 'slash',
   'http://slashcode.com/rss/1.0/modules/Slash/ section': 'section',
   'http://slashcode.com/rss/1.0/modules/Slash/ comments': 'comments',
   'http://slashcode.com/rss/1.0/modules/Slash/ hitparade': 'hitparade',


-huima