#1 Ask for alt-tag when inserting an image via image tool

[Andreas]

There sould be an extra question for the alt-tag for
the image or at least an alt="" in the source.

Justification:
Alt-tags are required for HTML 4.01 (see
http://www.w3.org/TR/html4/struct/objects.html#h-13.2\)

Unfortunately most users using HTML Editors don't
care/know about specifications.