update older centos/debian/ubuntu scripts from fen-vz3

Syncing latest changes from fen-vz3.

This also prepares the svn code to accept the changes published
venerable-vzcontainer-dawning github project

git-svn-id: https://svn.aptivate.org/svn/infrastructure/servers/fen-vzX/vz-bootstrap-scripts@10786 679a26be-e637-0410-a801-b7d8065a4221
centos6 scripts working on vz2 & vz3

centos6-x86_64 is known to be broken in fen-vz2.
After 'vzctl create' the server root doesn't get populated.
(server root is at /vz/root/228

git-svn-id: https://svn.aptivate.org/svn/infrastructure/servers/fen-vzX/vz-bootstrap-scripts@10787 679a26be-e637-0410-a801-b7d8065a4221
Merge branch 'master' into venerable