Auto expand rows

[GJNilsen]

When running the app on iPhone 6, after adding the third picture, it should be on a line below, instead of scrolling off to the side. The same way the text entry field expands downwards, the container of the cells should also expand accordingly.
(BTW, fantastic work done on the StackViewController)

[jessedc]

The demo app's implementation (ImageAttachmentView) uses a UIStackView in a container to deliberately lay out the thumbnail images horizontally in a single row to demonstrate the scrolling functionality of the stack view container class.

I think dropping additional icons onto new lines removes part of the demo app's functionality (as a demo) and is slightly outside of the scope of the demo project.

FWIW, UIStackView is documented to be limited to a single row or column, unlike UICollection view see Apple's docs on UIStackView:

The UIStackView class provides a streamlined interface for laying out a collection of views in either a column or a row

[indragiek]

@GJNilsen This was intentional, as explained by @jessedc (thanks!)