Unify Order/Cart repositories
Add ExpiredCartsPurger service
Add sylius:cart:purge command
Move purger service from Sales to Cart bundle
Simplify namespace
Use Datetime namespace
Rename PurgerInterface to be more generic
Remove chmod on removed dirs after 04a78191 to prevent Travis-CI errors
Prevent users reaching `/administration` url with 404 error
Force the redirect to the admin panel dashboard
Add SKU to Variant Form

Sku is already available in model, but not editable via admin.
This commit adds sku field to form and templates, and enforces unique validation.
Remove duplicated keys, extract translations
Extract DE translations and fix duplicated keys
Merge pull request #395 from stloyd/bugfix/admin-panel-route

Prevent users reaching `/administration` url with 404 error
Merge pull request #393 from Richtermeister/add-sku

Add SKU to Variant Form
Use real data in statistics table at dashboard
Merge pull request #397 from stloyd/bugfix/admin-dashboard

Use real data in statistics table at dashboard
Quick fix for gallery onclick event attachment on non existent element
Use the user provider instead of manager
Fix inventory handling during checkout
Add tax categories checking scenarios