Make Selected connection issue a warning if it receives data and there is no callback defined to process said data.
Minor Tidy
Handle status case where there is no IOError but the agent doesn't respond.
limit scope of exception trapping
Parameterize the default galil timeout
Improve Debugging messages
Change string form of unknown temps from UNKNOWN to U.
Add the messageTerminator attribute and use it in _terminateMessage
Override the new messageTerminator attribute
Add error_on_absent_terminator to receiveMessageBlocking and document.

If set to true error_on_absent_terminator will cause a ReadError to be
raised if the received message does not include the message terminator.
If set to a non-empty string that string will be used as the response.
Make use of error_on_absent_terminator to imporve error handling.