Initial pricing component and bundle

Conflicts:
	app/AppKernel.php
	src/Sylius/Bundle/CoreBundle/Resources/config/app/sylius.yml
	src/Sylius/Bundle/PromotionBundle/DependencyInjection/Compiler/RegisterPromotionActionsPass.php
	src/Sylius/Component/Promotion/Checker/PromotionEligibilityChecker.php
	src/Sylius/Component/Promotion/spec/Sylius/Component/Promotion/Checker/PromotionEligibilityCheckerSpec.php
Move registries to standalone component
Update registry class and interface references
Fix classes
Move specs, add features and fix composer.jsons
Spec the group based calculator
Rework the pricing extension and add templating helper
Fix the scenarios for group based pricing
Fix the form types generation for priceable
Update composer.jsons and travis configuration
Fix specs and travis config
Merge pull request #1382 from Sylius/pricing

Pricing
[VariationBundle] Improve code quality
Improve quality of most complex class/methods