Merge remote-tracking branch 'ogresCE/MAGETWO-36920-Use-dashes-instead-of-underscores' into MAGETWO-22864-system-maintenance-command-2

Conflicts:
	app/code/Magento/Indexer/composer.json
	dev/tools/performance-toolkit/framework/Magento/ToolkitFramework/Application.php
	dev/tools/performance-toolkit/generate.php
	setup/src/Magento/Setup/Fixtures/CartPriceRulesFixture.php
	setup/src/Magento/Setup/Fixtures/CatalogPriceRulesFixture.php
	setup/src/Magento/Setup/Fixtures/CategoriesFixture.php
	setup/src/Magento/Setup/Fixtures/ConfigsApplyFixture.php
	setup/src/Magento/Setup/Fixtures/ConfigurableProductsFixture.php
	setup/src/Magento/Setup/Fixtures/CustomersFixture.php
	setup/src/Magento/Setup/Fixtures/EavVariationsFixture.php
	setup/src/Magento/Setup/Fixtures/SimpleProductsFixture.php
	setup/src/Magento/Setup/Fixtures/StoresFixture.php
	setup/src/Magento/Setup/Fixtures/TaxRatesFixture.php