WrapLayout can't handle items with irregular heights

[roycornelissen]

For a requirement I was looking for an easy way to create a sort of moodboard with photo's of different sizes. The WrapLayout was a nice way to achieve that but I had to fiddle with the code to have it support photo's that have different heights. This version won't calculate the height correctly since it assumes that all items and rows have the same height.

My fork does this correctly, check this commit: roycornelissen@830aa42

Full file: https://github.com/roycornelissen/xamarin-forms-samples/blob/master/Evolve13/Evolve13/Controls/WrapLayout.cs

I think the code could be optimised a little bit, but for me it does what I want :)