Check if feeds need to be refreshed when showing the aggregate feed.

Fixes #46
Merge pull request #52 from eaburns/milestone/live

Check if feeds need to be refreshed when showing the aggregate feed.
Use the application name feed--me.

We also uploaded it: Fixes #20.
Merge pull request #53 from eaburns/milestone/live

Use the application name feed--me.
Remove index.yaml.

Nothing is indexed.
Add a comment.
Fewer writes on feed refresh.

Instead of deleteing all stored articles and adding all articles
fetched from the feed, just store new articles and just delete
articles no longer sent from the source.

Fixes #54
Merge pull request #56 from eaburns/dev/eaburns

Fewer writes on feed refresh.
Fix datastore.Put.

I guess that I didn't test this in a case where new articles needed to be put.
Limit number of articles added to the datastore.

Otherwise, feeds can serve hundreds of articles which would really be
hard on our quota. Other readers (like poor old Google reader) limit
their initial fetching to about 10 articles too.

Fixes #60
Use consts for datastore entity kinds.

Fixes #58
Merge pull request #61 from eaburns/dev/eaburns

A couple of small fixes
Only refresh feeds when showing their articles.

Previously, we considered refreshing stale feeds every time the
FeedInfo was read from the datastore. This was unnecessary.

Also, when adding a feed, it was refreshed. But, if the refresh failed
then the feed was never subscribed, and it's reference count was never
incremented even though the FeedInfo was put in the datastore. Now, we
don't refresh the feed until we actually want it's articles, so this
issues goes away.

Fixes #63
Use methods.

This way we don't need to reread the FeedInfo from the datastore in
some cases, and it allows for clearer names (f.articles, not
getArticles, etc.).
Better error reporting when displaying feeds.

Show successful feeds, and simply list any errors encountered in a
separate "article" at the top of the page. This is much better than
the previous behavior or sending an HTTP internal server error if any
of the feeds had an error.

Fixes #36
Merge pull request #65 from eaburns/dev/reporterrors

Better error reporting when displaying feeds.
Ditch unused vars in list.html
Add OPML import

I'm not particularly happy that it stops on the first error, but it'll
do for now. Fixes #21.
Make links in article titles look acme-ish

Fixes #27.
Style article header's lower border like an acme tag