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
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