Improve Exception Handling Documentation

As I state on my [Stackoverflow question](https://stackoverflow.com/questions/48218871/how-jersey-behaves-on-not-mapped-exceptions), I can't find any information about Jersey's behavior on uncaught `Exceptions` (`Exceptions` that aren't `WebApplicationException` and neither have been mapped with `ExceptionMapper`).

It would be great to know what's the expected behavior of some `Exception` that slips from our control and finds the `Jersey` container. This is specially important for security reasons, for systems that don't want to expose to the clients any kind of inner system state or variables.

I know it will take some time for this documentation to be made, so if possible, I would like to ask someone from the dev team to answer my Stackoverflow question, this will be very helpful for me and I believe for many others.