devs.invitation: rendered with special layout/style
Main font will be Tahoma. #53.

The old main font is Georgia which can be rendered correctly
and some characters are used in the font Times-New-Roman.

Now we switch to Tahoma. I tried with Verdana however the
result is not very good (the chars. seem too big)
devs.invitation: + footnote
devs.pos: new position (documentation system)