implement CapRefArray analogous to CapRef

[rottaran]

Each entry consists of a CapEntry and the original CapValue. The CapEntry points to the owning CapRefArray and contains the entry's index as capability data. The CapValue points to the destination object. The CapRefArray has an additional pointer to its owner and calls bind and unbind methods there to notify about revokation events. The bind and unbind methods are passed the CapValue to the destination object and the index in the array. The owner's type and the array size are passed as template arguments.