build rescue-server
install Yast packages via dependencies

- there can be different packages in SLES and openSUSE inst-sys
- make some branding packages optional (SLE branding has a different
  package set than openSUSE)
Merge pull request #8 from lslezak/yast_deps_and_branding

install Yast packages via dependencies
use skelcd-control-* for yast package list
no longer ignore certain yast2 packages
keep branding files all in the same image so relative symlinks work properly
better update-alternatives alternative for ruby
added aarch64
added aarch64 install file
ppc boot config changes
switch to grub for ppc
support setting OBS server via environment
start sshd without using sysvinit script (bnc #863029)
don't produce nonsense if the grub2 theme package is missing
set SLES boot theme temporarily to openSUSE as SLES branding is still missing
fix wrong ifarch s390x
ignore rake, rdoc and ri from ruby
fix ssl certificates (bnc #863788)
switch back to yaboot for a while
Fix branding image installation for ppc64le