store/memstore: recursively close objects

Make sure that ia object 'a' is closed, then object 'b' created
from 'a' is also closed, where 'a'->'b' are:
store -> transaction -> stream
store -> snapshot -> stream
store -> stream

Change-Id: Iebc3776f057bb988efb4f7ea6bdbfd0055abc8ca
10 files changed
tree: 9ad7ff05e6ca903b82002338475585b8fc8c3048
  1. services/