Fixed some deadlock conditions in LongRunningConnection.
The pending queries are now notified that they are cancelled.

In SendQuery there was a chance we could have a QueryInfo dequeued and the
connection closed. When returning from the method if the connection is
closed, we also now notify that the query is cancelled.
Small change. Force of habit caused me to ToList the queue and then
iterate over it. No need.
Merge pull request #73 from eplowe/master

Memory Leak/Deadlock condition with LongRunningConnection