Add replicated pool support to OSD logic

...in theory :-D now it needs some testing

osd_primary.h

@@ -20,6 +20,7 @@ struct osd_primary_op_data_t
     object_id oid;
     uint64_t target_ver;
     uint64_t fact_ver = 0;
+    uint64_t scheme = 0;
     int n_subops = 0, done = 0, errors = 0, epipe = 0;
     int degraded = 0, pg_size, pg_minsize;
     osd_rmw_stripe_t *stripes;