When a message is missing headers such as TimeSent, display appropriate defaults

[indualagarsamy]

At the moment, when a message is missing the TimeSent header and that message ended up in the error queue, ServicePulse could display the wrong duration. If SC sends the min date value, it could display 2015 years ago.
While the data needs to be cleaned up in SC, and SC should send in null dates when data is missing, the UI should still display proper defaults such as TimeSent value is not available for the missing values.

[weralabaj]

@johnsimons that was done as part of 194, was merged and can be released independently of SC changes. Can be closed.

[johnsimons]

Fixed in 91f5c61