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
Update registry class and interface references
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