Add export-autoyast to man page

Add export-autoyast section and a work flow example to the man page.
Add autoyast system registration to man

Add a section about the automatically system registration process with
autoyast.
Merge pull request #436 from SUSE/export_autoyast_documentation

Export autoyast documentation
Added missing check for rsync requirement in inspector
Set name of unknown operating system during inspection

This patch sets the name of the operating system if an unknown operating
system is inspected. If the name is left empty the system description
is invalid and useless to users. This patch allows to experimentally inspect
operating systems which are unsupported, yet.
Merge pull request #438 from SUSE/squashed_fixes_for_legacy_opensuse_systems

Squashed fixes for legacy opensuse systems
Add basic network setup to Autoyast export

Make sure that the automatic network setup created during the Stage 1
installation is kept since Machinery has no network inspector.
Add additional systemd states to Factory

Make sure to also generate descriptions with static and masked
services and also sockets.
Filter unsupported systemd services by default in Autoyast

Masked and static are not supported by Yast. It might also have issues
with the ".service" ending so we are removing it.
Make the exported autoyast profiles readable for all

Most HTTP servers run as a different user so having a restricted
mode configuration as for the machinery profiles doesn't make much
sense for an exported directory.
Filter log files from Autoyast export

There is an issue with a hanging gzip process if we export the log
files. Since they are not really needed in a newly built system we
filter them for Autoyast.
Fix Autoyast service creation
Automatically determine autoyast url