Add method to fetch the history and comments for a workitem

[vishal-kharde]

No description provided.

[fignutz]

Currently, workitem History is NOT reported in the OSLC API, but in the newer Reportable REST API that IBM uses. That said, I was able to hack the rtcclient library to pull in workitem histories. However, it is very involved and requires, aside from writing your own algorithm to sort the history return object (not the same as an OSLC object at all), creating a custom relogin function to "switch headers" on the fly within your RTC Class object: essentially bootstrapping your previous login with the new headers to talk to the other REST Service.

In other words, the REST headers that come pre-packed with the rtcclient library are incompatible with the RPT/Reportable API header. I doubt that the author (@dixudx ) will add this in anytime soon.

[dixudx]

@fignutz Currently I don't have too much bandwidth to work on this new feature. Your contributions are welcome if you are interested.