Feature Request: NGUI>Attach a Collider on inactive GameObjects

[loopyllama]

NGUI>Attach a collider adds a box collider to both active and inactive game objects, but it only correctly calculates the size and center on active objects. Please make this work with inactive objects as well.

On my end I found I could change NGUITools.cs in CalculateNextDepth:

1. UIWidget[] widgets = go.GetComponentsInChildren<UIWidget>();

to

1. UIWidget[] widgets = go.GetComponentsInChildren<UIWidget>(true);