Prevent unhandled netty errors from stalling writer

[tkaitchuck]

Problem description
When appending data to a netty connection a throttle is used to control the rate of transmission. This throttle is released when data is written to the wire successfully of if netty encounters an error and calls into its callback. It is however possible that there could be an error and due to a bug netty fails to catch it and does not invoke the callback.

Problem location
ClientConnectionImpl.java

Suggestions for an improvement
Add a try-catch block around the write call to make sure the callback is invoked upon exception.