Add some items to the todo list.
Improve styling in high-contrast mode. (Accessibility.)
Instant validation should register all changes, not just key events.

This is a problem for people using dictation software, or even just
pasting using the context menu.
Make instant validatoin work for textarea inputs.
Fix JavaScript coding style issue.
Remove on-blur event handlers that were messing up Tab navigation.

There were not really necessary. They just reduced the delay between
tabbing out of the input box, and when the validation happened. I
think we can live without that.
Stoutemyer's anti-derivatives of 1/(2+cos(x)) wrt x.
Prototype code to traverse a PRT added.
Update Installation/index.md
Updates to installation instructions.
Merge branch 'master' of github.com:maths/moodle-qtype_stack
Bug fix to https://github.com/maths/moodle-qtype_stack/issues/61
Update unit tests with id following automatic submission changes.
Add better alt-text to images.  Note, this does not yet include language independence.
Misc changes made following discussions with Tim.  Unit tests added for plots.
Many small changes following a meeting with Tim.
Updates to the documentation.
Typo.
Change alignment of inline equations (non-MathJax).

This is better for users of screen-magnifiers. Centered equations will
be difficult to find. A fixed distance from the left margin is better.
Rename table qtype_stack to qtype_stack_options.

Sadly, we started before the convention was firmly established, and then
the naming convention went the other way.