[PATCH] Documentation: Fix user-manual.txt indentation to comply to asciidoc format (also fix po4a translation tool usage)

[Dirk Hohndel]

This is the second patch that you send that has 'y' as encoding instead of
utf-8 - which breaks my tooling for applying patches.

Is there a reason why you send out attachments with that invalid encoding?
Could you fix it and resend?

Thanks

/D