Add autoResizingMasks to the iOS example, plus set KGNoiseView to redraw upon bounds change

Hey David,

Awesome Obj-C component--particularly with regard to iOS/OSX consistency and support. It's a great learning tool.

As a mostly iOS guy, I felt that `KGNoise`'s iOS example was a step behind the OSX example. The OSX example handles view resizing gracefully, yet the iOS example does not. I added a few `autoResizingMasks`, and iOS handles it gracefully. One missing step from there: `KGNoiseView` does not redraw on iOS after a frame change (`UIViews` typically don't by default). Setting `KGNoiseView`'s default `contentMode` to `UIViewContentModeRedraw` in `-(void)setup` causes it to redraw after a bounds change.

These are relatively minor changes, but if you compare the previous iOS example to the updated example, the change is pretty stark.

Hope you like it, and thanks for the great component,
Daniel