<cucumber> Refactoring upgrade_steps.rb to be cart-agnostic

Refactored stepdefs to derive "expected" cart versions from manifest
provided in cart RPM package

Refactored some stepdefs to require component version to be specified
(i.e. the 5.1 in mysql-5.1) to eliminate hardcoded version numbers in
stepdefs

Refactored feature tests to use new stepdef formats