Add onChangeEnd handler

[bryanjclark]

Hi! I was running into an issue with allotment where its onChange handler's constant-firing was creating some performance issues in a webapp that I'm working on.

I'd like to propose adding an onChangeEnd callback, which gets called exactly-once when the user either (a) stops-dragging-with-their-mouse or (b) clicks Reset for the layout.

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[masesk]

Check this:
#576

[bryanjclark]

Looks like my PR is no longer needed - closing!

[johnwalley]

Hi @bryanjclark. Do let me know if there is anything missing in the merged PR that isn't in yours. I really appreciate you taking the time to put together a PR and it's just the fact that I'm merging things in the order they arrived 👍.

[bryanjclark]

Oh it's all good! I'm just excited to have the functionality - was getting some weird lagginess in our frontend from the constant-calling-of-the-callback-function (even with debounce somehow?) so I'm glad there's now an option to just get an update once the drag is complete. Cheers!