Bug #58, New WP action "slickquiz_save_quiz" - PHP component

* As detailed in the bug/ issue report, a way to save extra data
* https://github.com/jewlofthelotus/SlickQuiz-WordPress/issues/58

git-svn-id: https://plugins.svn.wordpress.org/slickquiz/trunk@916761 b8457f37-d9ea-0310-8a92-e5e31aec5664
Bug #58, Set a callback to add extra data sent with Ajax POST - JS

* Needs work!
* Javascript to complement the PHP modifications in previous commit
* New public function `$.fn.setPreSaveQuiz(function () { return extra })`

git-svn-id: https://plugins.svn.wordpress.org/slickquiz/trunk@916762 b8457f37-d9ea-0310-8a92-e5e31aec5664
Bug #58, Tidy up the Javascript callback mechanism

* Public JS function `$.fn.setPreSaveQuiz(function ( return extra ) {})`

git-svn-id: https://plugins.svn.wordpress.org/slickquiz/trunk@916764 b8457f37-d9ea-0310-8a92-e5e31aec5664
this git/svn setup is killing me

git-svn-id: https://plugins.svn.wordpress.org/slickquiz/trunk@916765 b8457f37-d9ea-0310-8a92-e5e31aec5664