Another transition adjustment.  #1557

While QAing I noticed slides where going a lot faster in 3.3 than 3.2.  I think it's a difference between the libraries.  Flex appears to run a slide for its duration, run a transition, then start the timer for the next slide's duration.  Reponsive appears to start the next slide's duration during the transition.

To make responsive behave like flex so nobody notices a difference, I added the transition time to the duration.  Incidnetally this also fixes the previous problem with duration and speed needing a 100ms gap between them.
Merge pull request #1829 from openscholar/1557-qa_duration_bug

Another transition adjustment.  #1557