This command gets the api level from tt-rss, this doesn't serve any
purpose yet, but it could be used later-on to determine which features
are and aren't available.
Before, when attempting to log in, and failing, the username and
password were retained and subsequent attempts would also fail. Now
the data is deleted and new login requests will start fresh.
* avandu.el (avandu-entity-replacement-alist): An alist that keeps
track which titled entities should be replaced by which character.
(avandu-clean-text): New function.
(avandu--insert-article-excerpt): Don't run endless chains of
`replace-regexp-in-string', leave (almost) all cleanup to
`avandu-clean-text'. Don't print an excerpt if it is empty.
* avandu.el (avandu-overview-excerpt): New face.
(avandu--insert-feed-title): Replace `newline' with `insert-char' to
prevent newlines from continuing indentation.
(avandu--insert-article-title): Replace `newline' with
`insert-char'.
(avandu--insert-article-excerpt): New function.
(avandu-list): Ask tt-rss to send along an excerpt of each article
and print this excerpt after the article's title.
