Bug #1, JuxtaLearn Quiz - defensive "group by" SQL in [quiz_list] shortcodes

* Plus, fix HTML ordering issue - "ob_start()" in other WP shortcodes
Bug #9, JuxtaLearn - edits to custom styles/ CSS for ClipIt menu-link
Bug #7, Alter the "juxtalearn_quiz_scaffold" database table

* Add UNIQUE constraint to the "quiz_id_index" KEY,
* Add a "clipit_id" integer column
* Bump DB version to 1.3
Bug #11, Fix missing legend in JuxtaLearn Quiz spider chart

* Fix - duplicate ID
Bug #6, Fix readability of Javascript code (JS Lint) - JuxtaLearn Quiz

* Re-instate missing "ob_start()" in [quiz_score] WP shortcode
* Add "?intervals=5" chart levels/ divisions
* Follows on from Bug #11 fix
Bug #5, Increase font-size(s) in JuxtaLearn Quiz radar/spider chart

* PHP class variable feeds through to Javascript - for SVG font-size
* Also, extending use of "?debug=1" HTTP parameter
* Accessibility/ readability of chart
Bug #1, Improve readability of JuxtaLearn Quiz radar-chart embeds

* Bug #5, Accessibility - simplify headings
* Bug #3, Simple embed - reduce margins, heading font-size, embed space
Bug #1/ #6, Further tweaks to SVG positioning in JuxtaLearn Quiz visualizations
Merge branch 'juxtalearn' into jxl/CR8/api