[Pacemaker] Rolling upgrades from 0.6.x to 1.0.x

[Andrew Beekhof]

It appears that, despite the best of intentions, rolling upgrades from  
0.6.x to 1.0.x simply don't work.
The problems are particularly obvious for Heartbeat users, but also  
exist for those running OpenAIS.

Measures have been put in place (a new automated test) so that we  
don't encounter this problem again, however the issue now is what to  
do about the current breakage...

I'm happy to put the effort into fixing it if there is sufficient  
demand, but it will be a non-trivial task and the time could be better  
spent elsewhere if everyone has already moved on to 1.0.x.

So if the subject is important to you, please speak up :)

Andrew