[gp11] Open readonly sessions when enumerating objects.
[gp11] Open readonly sessions when enumerating objects.

 * This is an interim measure. When GP11 is redone the API
   should allow the caller to specify this.

stefwalter/gcr,Distrotech/gcr,stefwalter/gcr,stefwalter/gcr,Distrotech/gcr,stefwalter/gcr,Distrotech/gcr,Distrotech/gcr