Code review comment for lp://qastaging/~3v1n0/unity-2d/fix-multiscreen-indicators-geometries

Hi Marco, excellent work! I will test it soon, just looking at the code for now :-)
Meanwhile, a couple of comments:

- Making the Unity2dPanel as implicit parent for the IndicatorsManager can cause confusion. For instance, one could call IndicatorsManager::setParent() and break our assumption. IMHO it's better to have a separate method IndicatorsManager::setPanel(), or a constructor which takes both a Unity2dPanel argument and a parent QObject.

- Member naming: getID() -> id()

- "d->q" = "this" :-)