Functional testing plan (test cases, e.g. for non-technical manual pre-release testing)

[Aleksej]

Some quotes from IRC: ======

<paroneayea> I think there's two things to that, we could use more unit tests, but we could also really use a functional testing plan
             that is, a list of steps that somewhere before release time people can go through and test the software and make sure everything is working as expected
…
<paroneayea> we could probably use omgmg for it.
…
<AVRS> Mozilla uses Litmus, but it's going to be replaced.
…
<paroneayea> even just a wiki page detailing procedures would be good, but a better tool like Litmus or a replacement would be nice

<paroneayea> so this type of testing is less technical
             it's more like you list a whole bunch of steps to test
             like, submit a large image, see if it resizes right
             register with a goofy username, see if it breaks
             etc
             make sure that all of the expected functionality works from a user-clicking-through perspective

---

Example of Litmus test results: https://litmus.mozilla.org/search_results.cgi?test_run_id=83