socket connection teardown failure

[lasch]

I discovered that a disconnecting socket client causes the server to crash. Looks like something is stomping on memory. I couldn't fix it today but the other update/fix was important enough to push it.

[lasch]

The memory corruption should be fixed now. However, the connection tear down only looked reliable for well-behaved clients.

[lasch]

pull request #41 should improve the robustness for failing or interrupted clients.