[Merge] lp:~mterry/qtubuntu/greeter-is-shell into lp:qtubuntu

[Michael Terry]

> Why both and not just the first option?

A) To match the existing code examining "unity8" or "/usr/bin/unity8"
B) So that we don't have to update qtubuntu when/if a launcher script changes its mind about using the full PATH name.
-- 
https://code.launchpad.net/~mterry/qtubuntu/greeter-is-shell/+merge/220543
Your team Ubuntu Phablet Team is subscribed to branch lp:qtubuntu.