Window resize panel recalculation firing too often and sometimes failing to resize correctly.

[b-zurg]

Just a few more callbacks than I would have expected for a debounced resize. It's a bit of an edge case but for cases where people are using this lib in an app this might come up more often than you'd expect.

Additionally if a pane is collapsed and the resize makes the window bigger then the recalculated flex-basis is not correct.