ENH: allow the psychopy app to --run a python script without loading the app interface
BF: MultiStairHandler was running over by one trial on each stair

It needed to test whether the staircase had finished (not at the point
of the next trial starting but at the end of the previous).

Also added a test to the suite to catch this in future
FF: trying to fix travis issue with commit 5712203561

Travis running the test suite fails to create an app. I'm guessing that
travis has '--run' or '-r' in its calling args and the app now treats
these as saying "run file don't load app"
Merge branch 'master' of github.com:psychopy/psychopy
Revert "ENH: allow the psychopy app to --run a python script without loading the app interface"

This reverts commit 5712203561b461f62b4188fc4bed7372b8193162.
Revert "FF: trying to fix travis issue with commit 5712203561"

This reverts commit cf366fc8d18e3ee85d7d999f233d881c3dab2a19.
Merge pull request #680 from peircej/master

Fixed bug in multistairhandler