MAGETWO-85297: 8410: Custom Checkout Step and Shipping Step are Highlighted and Combined upon Checkout page load #975

 - Merge Pull Request magento-engcom/magento2ce#975 from RomaKis/magento2:8410
 - Merged commits:
   1. fd5f40a9
   2. c12dc31b
   3. 04ff6611
   4. fccecf38
   5. f7289237
   6. a0b5460f
   7. 98e7951b