Altered:
```IDEASXASScanConfigurationView``` to call ```onROIChange()``` when the
detector choice has been changed.

Altered:
```IDEASXASScanConfigurationView::onROIChange``` to check if 'none' is
selected for the current XRF detector before trying to access the set
ROIs for it.
Update IDEASXASScanConfigurationView.cpp

Altered:
- The form of the code so that it didn't just have return statements in the middle.  There is no change to functionality.
Merge pull request #872 from acquaman/Issue867

Pull request for Issue867: IDEASXASScanConfigurationView ROI warning ignores selected detector