Javascript library to parse JuxtaLearn cookies, and display the user's name etc.

* IMPORTANT: this is not an "authentication" library.
* You should protect sensitive pages with the JuxtaLearn_Cookie_Authentication PHP library.
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Re-worked "JXL_Cookie" Javascript/ JS
Bug #2, Adding function to set cookie for user's email address

* Plus, parsing, documentation, test.php, Javascript,
* Some re-factoring of PHP library to aid readability,
* https://github.com/juxtalearn/juxtalearn-cookie-authentication/issues/2