Versioning

[sergey@total-knowledge.com]

> New versions aren't created even if object links
> are changed, until object is published. I know we didn't think through this
> part of editing scenario 100% yet.

Let's look at this more thoroughly.
If
> New versions aren't created even if object links are changed
then it means that Students that currently studying a Course which
contains this UMO will see the Course that structured differently than the
one they signed-up originally.
Are we OK with that?
Also it means that if Author adds completely new UMO from Repository to
his Course and doesn't check this action as "versioned", Students will see
this new UMO during studying process. Probably for this scenario we have
to completely remove "minor change" option from the UI which leads to some
additional functionality which will allow us to check whether it's new UMO
for the Course or Author just manipulating with existing one and it's OK
for Students to see that.