The videos have to be resized after each step is displayed,
because they are sized to fit into their container at load time,
but since the container isn't visible at load time, the videos
end up with wrong dimensions.

Trigger video resize after displaying each step.

The scrollIntoView function can be called multiple times,
which resulted in multiple (10+) scroll animations getting queued.

After the first animation successfully scrolled to the top of the step,
the others kept running one by one. The animations weren't visible
because the element was already scrolled to its final position, but if
you tried manually scrolling down while the animations were still running,
the window would be scrolled right back up.

A small light grey copyright notice is displayed below the buttons
of mentoring and step blocks.

It is hidden in the apros theme.

Also includes a drive-by fix that makes integration tests for plot
blocks more robust.

Fix a few layout issues in Step Builder

Refactored Step Builder Messages

* Change conditional message configuration to strings (better XML)
* Don't use student_view for embedded content in Studio or XBlock workbench

Step Builder: Fix JS error that causes crash if no review step is present

Step Builder: Make sure tooltips for plot points work across different browsers

Fix various bugs found in QA

Add instructional message to step blocks.

Making MCQ use message attribute the same way MRQ does

Step Builder: Interoperability for scale and plot blocks

Step Builder: Support for additional overlays for plot blocks