Add old site contents for transition

As part of https://github.com/fontforge/fontforge.github.io/issues/25 I got access to the old SF.net FTP area, and I see that it uses a `.htaccess` to redirect visitors to http://fontforge.org; so we can
- [x] move the pages to here at the same URLs, so nothing breaks
- [x] insert a message about the transition at the top of each old page, and 
- [ ] merge this pr 
- [ ] update the `.htaccess` on sf.net to redirect to http://fontforge.github.io instead
- [ ] ask Toby Thain to repoint the DNS A entry to Github's IPs
- [ ] as each old site page's content is moved to a new site page, cut it down to a redirect 

My initial message is,

> This is part of the old website. New website begins at fontforge.github.io
> 
> Are you a web developer? Help us migrate this page on Github