Profile and optimize tree insertion

[hdeshev]

We can probably do better at inserting visual elements. The goal is to see if we can get somewhat closer to the browser performance.

[0cv]

It may be related with the issue you reported - but I indeed noticed "relatively" slow performance by doing something relatively simple. I just took the todo sample application (https://github.com/NativeScript/sample-ng-todomvc) and displayed through a for loop 100 items (instead of 2). Then, once the application is loaded, I tried to delete one of the first item, and somehow, when looking at the logs, it redraws entirely the whole list and it blocks the UI for 3 to 5 seconds (not on an emulator but on my galaxy s4). On the opposite, deleting one of the last items (bottom) of the list, it redraws almost instantly.