PE: Fix application of rsc_location constraints for groups in non-symmetric clusters

rsc_location constraints need to be applied to all members of a group

(because symmetric-cluster may be FALSE).

The only thing we need to do differently for colocated groups is apply

it with a score of 0 to everyone but one of the nodes.

Mercurial revision: dd5b0a0f79cc1d4ac264d73f443fe137c4a16aeb