[FEATURE ember-eager-update-url] Eagerly update link-to urls

Previously, the url in the address bar would only update
at the very end up the transition. This change causes the
url update to happen immediately unless the transition
was aborted/redirected within the same run loop, which
provides for a better UX 99% of the time.
Merge pull request #4122 from machty/eager-url-update

[FEATURE ember-eager-update-url] Eagerly update link-to urls
[BUGFIX release] We don't need to call didChange after we've copied
[FEATURE ember-eager-update-url] tweak for hash location

Need to strip hash before eagerly updating url.
Add documentation for Ember.EnumerableUtils.
Merge remote-tracking branch 'upstream/master'