Use memquota queue for channel->circuit RX data
This branch is on top of !2509 (merged); you should start at "memquota: impl HasMemoryCost for ClientCircChanMsg"
Fixes #1682 (closed)
This branch is on top of !2509 (merged); you should start at "memquota: impl HasMemoryCost for ClientCircChanMsg"
Fixes #1682 (closed)