Avoid/Reduce Layout Thrashing in hinting script

[fanglingsu]

The hinting script uses a lot of methods that measure the style and dimensions of DOM-Nodes which causes syncronous Recalculations of the layout wich is expensive see https://developers.google.com/web/fundamentals/performance/rendering/avoid-large-complex-layouts-and-layout-thrashing It's the target of this issue to find/evaluate a method to avoid some of the recalculations to speed up the hinting JavaScript (https://sking7.github.io/articles/449317090.html).

[stale[bot]]

This issue has been automatically marked as stale because it has not had activity within the last 60 days.