Add another CentOS5 workaround

On this ancient distro the "mount -L" used by ONE's vminit doesn't
discover the volume unless it's already in blkidtab.

While ONE checks for the symlink /dev/disk/by-label/CONTEXT symlink
first it then resorts to "mount -L". So make sure we have an entry in
blkid.tab when contextualization starts.
Merge pull request #34 from agx/fixes/centos5

Add another CentOS5 workaround
ssh: add authorized_keys and ssh config also to oned host
Merge pull request #35 from nmesstorff/oned_authkeys

"ssh: add authorized_keys and ssh config also to oned host"
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it's not easy to be green ;-)