Merging 'develop' into 'mockup'

Conflicts:
	app/controllers/plazr_store/admin/products_controller.rb
	app/controllers/plazr_store/admin/variants_controller.rb
	app/controllers/plazr_store/pages_controller.rb
	app/models/plazr_store/product.rb
	app/models/plazr_store/variant.rb
	app/views/layouts/application.html.erb
	app/views/plazr_store/admin/products/_form.html.haml
	config/routes.rb
	test/dummy/config/routes.rb

* => Most conflicts were solved by replacing the old mockup code with the
* new develop one. Where in doubt, the old version was kept commented
* for future reference.
Fixing functional problems.

+ db:populate working again
- commented most of topnav (the application layout was breaking with
  plazr_auth
+ added plazr_auth nav (for authentication)