High: PE: Clone colocation fixes
Clone colocation constraints were only being applied to the first instance
which is clearly wrong and meant that anti-colocation between clones did not
function at all and clones were often allocated in the wrong order which
impacted master placement.

Part of fixing this included creating a global list of colocation constraints
(just like rsc_order and rsc_location constraints) and free'ing them from there
instead of when destroying resources. This allowed multiple child resources to
reference the same constraint.

Mercurial revision: 2df01f1a3de95b3b4d7a23bcfcf4403172188bb6