[BUGFIX beta] Add unit tests for AutoLocation.

Conflicts:
	packages/ember-routing/tests/location/history_location_test.js
[BUGFIX release] Add missing HistoryLocation code that was lost in manual merge from es6=>stable
[BUGFIX release] Ensure that AutoLocation gets `rootURL` as an option to `create`.

Fixes #4704.

AutoLocation makes decisions about replacement URLs that depend on the `rootURL` setting of the router, but the router was only providing the value of `rootURL` after `AutoLocation.create` was already called, making it not respect the `rootURL`.\n\nTo fix this issue, this commit introduces a `settings` injection type.  This type is private for now. The `root-url` setting is either `null`, the default, or a string value taken from the public API of `Router#rootURL`. `settings:root-url` will be injected as `rootURL` in all objects of `location` type.
[BUGFIX release] Assert rootURL has trailing slash when used with AutoLocation + additional test coverage
Merge pull request #4730 from jayphelps/missing-history-stuff

[BUGFIX release] Add missing HistoryLocation code that was lost in manual merge from es6 => stable
Merge pull request #4731 from jayphelps/stable-auto-location-fix

[BUGFIX release] Manual merge PR for #4717 into stable branch
Revert "[BUGFIX beta] Total invalidation of arrayComputed by non-array dependencies should be synchronous"

This reverts commit 7af8beb0bb9e484ab7427b447f6b6dbb76b4aad8.

See #4740 for details.
Publish 1.5.1.