use custom layout invalidation context to suppress unneeded computations
lazily update cell’s layout constraints
lazily update cell’s text view
do not use concurrent enumeration
avoid expensive view hierarchy modification during cell configuration
Revert "avoid expensive view hierarchy modification during cell configuration"

This reverts commit 3f7b5ae86fcd85fe822b02d769a8900b6760ef3c.
Merge pull request #313 from erysaj/issue_281_improve_cpu_springiness_cpu_usage

Improve springiness cpu usage