Use standard Kiwi export format

[cornelius]

Kiwi defines a standard export format, which is used by SUSE Studio and OBS. Machinery should be able to support this.

[coogor]

For cpmpleteness, my comment from #1301: KIWI from studio behaves different than on OBS than on local build. Machinery I haven't tried. But just taking the sources from lets say Studio and drop it to OBS does not work....

[thardeck]

The format is documented here: https://fate.suse.com/318388

[coogor]

This page seems not to be public (You are not allowed to access this service.) I cant access it with my openSUSE credentials

[thardeck]

I was not sure if it is available.

The kiwi configuration exchange format is:

• a tar ball compressed with xz.
• it contains a "config.xml" at top level. This is a required file.
• further optional files, like image.sh, config.sh and alike are packaged as well on top level
• All layered files are inside of the directory called "root/" inside of this archive
• The file name suffix of this archive should be .kiwi.txz