This adheres more closely to the specs, especially Atom, where the
'description' arg becomes <summary>.
Note that this means full article content will no longer appear in RSS
feeds.
publication time and date and the last modified time and date
independently.
This makes it possible to access the last updated date with {{ article.locale_modified }} in templates.
Additionally, an already delivered feed entry can be corrected by changing the modified date and time, as it is used for atom:update
/ rss pubDate field now.
I'd added them earlier to test that a configuration edit could
preserve the original output locations. However, it is likely that
you have quite a number of static files, and we shouldn't recommend
listing explicit paths for all of them. With this configuration
change, the pictures will be copied into the output directory using
their original relative path (e.g. `pictures/Fat_Cat.jpg` without the
`static`). Any |filename|-style links will be updated automatically.
If you *want* the pictures to end up in a `static` directory, it's
easier to just organize your source that way.
