Expose Scenario id to step definitions

Extend the Scenario interface with the method getId(). Then it is
avialable to step definition through the Scenario argument to hooks.
The scenario id is esentially <feature name>;<scenario name> or
<feature name>;<outline name>;<example group name>;<example row number>.
Javadoc for getName already added to master
Merge branch 'expose-scenario-id-to-stepdefs' of https://github.com/brasmusson/cucumber-jvm into brasmusson-expose-scenario-id-to-stepdefs
Attribution. Closes #673, #715
Merge branch 'brasmusson-expose-scenario-id-to-stepdefs'