MAGN-5245 Create UI example node.

http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-5245

PTAL:
- [ ] @lukechurch 

Require Merge:
- [ ] Revit2015
Probably worth adding a third, calling a function - or a pointer to the other classes where more can be found. Given that we want to replace this API, probably don't need to do much more than that at this stage.