Reminder to work on the hints.
Fix whitespace
Add missing form field types.
Experimentation with differential operators.
Merge branch 'master' of github.com:maths/moodle-qtype_stack
Fix to issue #67
Only include .md files in the sitemap (mostly to stop listing irrelevant .bak files)
Confirm end of script.
Tightening up the support for \$ as a currency symbol.
Update the docs
Better support for strings within casstring types.
Now use the answernote field of the casstring class to hold intelligent notes about the PHP invalidity.  This will be useful when reporting.
Support for actuarial notation.
Decimal placed answer test: added in unit tests
Fix formatting error in Answer_tests.md

Thanks to Ben Brawn.
Block out access to decimal places test - this does not yet work.
Merge branch 'master' of github.com:maths/moodle-qtype_stack
Better error reporting when empty results are returned.
Better error reporting when empty results are returned.
Merge branch 'master' of github.com:maths/moodle-qtype_stack