Mask media message bubbles with bubble image (with "tail")

[jessesquires]

• create an image masker object
• mask photo items
• mask location items
• mask video items

[LeoNatan]

In my own implementation I used the bubble image as the content of a mask layer to achieve this. One gotcha is that when auto layout resizes the image, it somehow directly manipulates the frame of the layer, so I had to subclass the image view, return a custom class, and when its frame changed, updated the mask layer's frame to be the same. It works well.

[jessesquires]

Thanks @LeoNatan !