* gnus-art.el (gnus-article-edit-part): Don't jump to nonexistent part.

* gnus-art.el (gnus-article-edit-part): Don't jump to nonexistent part.
(gnus-mime-view-part-as-type-internal): Default to text/plain for text parts,
 or application/octet-stream as a last resort.
(gnus-mime-view-part-as-type): Don't toggle display.
(gnus-mime-view-part-as-charset): Don't turn off display before querying
 charset.

* mm-view.el (mm-inline-text-html-render-with-w3): Don't add XEmacs stuff to
 undisplayer function in Emacs.
(mm-inline-text-html-render-with-w3m): Remove Emacs/W3 stuff.

* mml.el (mml-generate-mime-1): Prefer utf-8 when encoding text/calendar parts.