[M2] APT and Umlaut

[Daniel Frey]

For full internationalization I think APT should be able to handle umlauts. How 
do I code umlaut in APT? xdoc does accept umlauts, APT does translate them into 
something non-readable. Example
 
    Einführung --APT-->  Einführung
    Einfürung --APT-->  Einfürung
 
I tried to save the APT document as UNICODE, UTF8, but with the same result. 
Any ideas are welcome.
 
Thanks in advance
Daniel Frey