Add support for new openSUSE Leap releases. Moreover, document
common environment variables and remove old note.
Change-Id: I8cf0b215cb4d9231e5658d49e3fd598dfbb5fd37
The fix for static links to the latest image has been rolled out.
Update documentation accordingly.
Change-Id: Ic92d0e1d584ca2bf1d82f411102079cb4455bddb