bootstrapping an instance.

If we don't dont this, the portal._setObject('portal_types', ...) call while
creating a new site will fail because it will force unghosting the portal
type class of "Types Tool", which is not possible this types tool is not
installed yet.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@42441 20353a03-c40f-0410-a6d1-a30d3c3de9de