Add a help/lang file location rule for course import modules

In lib/moodlelib.php insert into the list of array initialization values (e.g. line 5297) the following:

'import_' => array('course/import'),

This will enable a custom import plugin to be contained in the single sub-directory (course/import/[pluginname]).

You can guide the get_string routine by supplying the location in which to look for your lang file, but the helpbutton() doesn't provide a similar way to locate help (html) files.