CONTRIB-4314 :: In accordance with current Moodle languages policy, all language folders other than English have been removed from the lang folder. All translations are now available from AMOS.

Signed-off-by: Joseph Rézeau <moodle@rezeau.org>
renamed README file to readme.txt in accordance with the moodle plugins repository prescriptions
plus added release info to readme.txt

Signed-off-by: Joseph Rézeau <moodle@rezeau.org>
CONTRIB-4304 Restructure lib.php by Jenny Gray

Signed-off-by: Joseph Rézeau <moodle@rezeau.org>