Insert adjacent child views in batches rather than
individually.

This will, for example, improve the rendering
performance of #each when initially rendering an
unloaded RecordArray.

A common workaround to this issue was to wrap your
#each inside an {{#if isLoaded}}.

ht: @kselden
Add {{input type="text"}}
Add Ember.Handlebars.helper
Add support for {{input type="checkbox"}}
Extract a private ViewCollection class to aid in
manipulating several views at once.
Improve the performance of view notifications and transitions.
Avoid recursively calling transitionTo.
Match the transitionTo APIs.

When we know we have the full hierarchy, pass false.