Calling router.map now appends the routes instead of replacing them

I would have added a test but there did not seem to be any route
generation tests.
Revert "Use Ember setter to set Ember.Route controller."

This is intentionally not-observable

This reverts commit 693119d65bada2fe16bba90c2bafacf9db8e470e.
Added functionality to Router.map to allow it to be called multiple times without the map being overwritten. Allows routes to be added at runtime. One test with multiple cases also added.

Conflicts:

	packages/ember-routing/lib/system/router.js
Merge pull request #2892 from igorT/router_append

Calling router.map now appends the routes instead of replacing them
Update router.js. Fixes #2897.
Merge pull request #2898 from machty/borf-snorlax

Update router.js. Fixes #2897.
Stringify linkTo examples
Updating new Ember.Component documentation to remove confusion
Merge pull request #2900 from bartsqueezy/master

Updating new Ember.Component documentation to remove confusion
Improve docs

More info on optional parameter and fix typo
Merge pull request #2901 from raulbrito/patch-1

Improve docs
Merge pull request #2899 from machty/string-link-to

Stringify linkTo examples