feat(omaha*) move to new config file locations

We do not parse /etc/lsb-release anymore, instead the following two
files are looked at, with the following key values:
  /usr/share/coreos/release
    COREOS_RELEASE_VERSION
  /etc/coreos/update.conf
    SERVER
    GROUP
Merge pull request #16 from gregkh/master

feat(omaha*) move to new config file locations