Couple of defines for building against PRMan17.

A couple of minor modifications to CoreRI so it compiles against PRMan 17.

Specifically PRMan does not have the PkProgressiveQuery display query type. Also, PRMan's SLO library doesn't have the annotation methods. It does have some support for meta data though - http://renderman.pixar.com/resources/current/rps/sloApi.html#meta-data. Maybe it could provide equivalent functionality?