Generic Moodle license boilerplate

As per comments at
https://moodle.org/plugins/view.php?plugin=local_tdmmodatcursor
Drop the Y.Moodle namespace in favour of Y.M

As per David's comment here:
https://moodle.org/plugins/view.php?plugin=local_tdmmodatcursor

And the Moodle documentation:
http://docs.moodle.org/dev/YUI/Namespacing
Replace double quotes with single for consistency
Drop unused data-below property
Use Moodle language string substitions instead of our own formatting
Partially resolve the "editing multiple courses in one session" bug

As pointed out by David Mudrák:

    Your solution based on $SESSION->local_tdmmodatcursor_addabove may
    lead to an unexpected behaviour if the user is editing the same
    course in multiple browser windows in parallel. The observer then
    moves any newly created course module, whichever comes first. I
    admit it's not really typical use case though.

We can't solve the problem within courses with the current
implementation, as this would entail knowing the ID of the created
course module before it's created. We can prevent against changes across
courses by making $SESSION->local_tdmmodatcursor_addabove an array and
indexing the "below" CM IDs by the course ID.

It's not perfect, but it's definitely an improvement :)
Bump version to 0.3.0

Seems I didn't bump to 0.2.0 when I tagged it... oops