Handle namespace collision warnings

This handles namespace conflicts warning when you use a class that conflicts with different class names the namespace hierarchy.

@ke-yu @aparajit-pratap 

Ive cleaned up the conditions.
For now, i think the class checks will need to be separate because the second one checks conflicts on an identifier only. This can only be done after doing the first check on conflicting given an identifier list.

Ill add this not to the refactor defect in: http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-5221