Add code to clientDisconnected(...) slot to clean up connection
Add code to clientDisconnected(...) slot to clean up connection

When a client is disconnected it needs to be removed from the
lookup table. Also any endpoints keyed on molequeueids associated
with the connection need to be cleaned up.

Change-Id: Ib43579b436a9395009f5fcf88763b30384f37479

OpenChemistry/molequeue,OpenChemistry/molequeue,OpenChemistry/molequeue