Prefix yocto build with concrete yocto SDK version

Currently, we provide the lib in some folder which is just called "yocto". Since yocto will be available in different versions, we should prefix the folder with that version in order make clear which concrete SDK was used.

Afaik the version can be read out from some "image-manifest" (or similar) file inside the Yocto SDK folder.

The build should always run against the "current" yocto version, since that one is considered to be stable. ("current" is supposed to be added to the yocto SDK path soon)