Revert "call _reuseChildren in _syncChildViews only if we really need to create"

This reverts commit 2e37a552ad6a44f2341b2ebe1a259a899139448b.

This change was making the grouping expand not working in some cases
Make childViews in _reuseChildren be updated by content index order like
it happens on line 867.

In case of frequent updates (every second) of the content, the fact that
it the childViews were referenced by content index was causing an
unnecessary change of position of childViews.
Cleaning unused vars and code formatting
Release