explain hints
Changed loop in randRangeUnique to include the max value
Added boxes to completing the square exercises
Remove linting stuff from extract_strings.py and update the Makefile.
Change acceptable formats to integer
Acceptable formats says integer
Update multiplication_2.html
Update multiplication_3.html
Revert earlier run of the linter against the exercises.
Fix some additional, ambiguous, i18n cases.
Add function to generate regex to capture an expression
Semi-colons and tidying
Fix if statement
More Semi-colons
Add assumption that variables are not equal to zero
Add condition to final exercise and simplify everything
Fix simplifying_rational_expressions_3 answer form

Fixes bug introduced in 7c3047bf0232a4ef652b21c00b718a0036826a8a.

Auditors: peter
Remove second hint when unneccesary
Re-fix the exercises after fixing a number of bugs in the linter.
Finish documenting the lint_i18n_strings.py script.