revert: fix(Scope): aggressively clean up scope on $destroy to minimize leaks
revert: fix(Scope): aggressively clean up scope on $destroy to minimize leaks

This reverts commit f552f25171390e726ad7246ed18b994970bcf764.

The commit is causing regressions.

Closes #6897

campersau/angular.js,campersau/angular.js