addressed issue of enter not submitting login form, and (I think) the country form picking up user's country, if set

fixing mysterious layout regression making main nave and panel vertical spacing and panel-body text width strange

started cleaning up header.php and removing user-level prefs, as opposed to course-level prefs, from update form

Adding functions-api.php as it was part of the theme but not previously added. Doing this as I need to recreate this theme on a test multisite install, wpms.oeru.org

Don't depend on global $user_ID, $user_email

Fixes #43

Replace get_currentuserinfo with wp_get_current_user.
https://codex.wordpress.org/get_currentuserinfo

Closes #43

If an [oeru_idevice] shortcode is given an optional id attribute,
it is used as an HTML id on the containing DIV. This allows using
it as a named anchor for scrolling to a particular part of a page.

Resolves #42

If the scan page was not enabled, the toggle button was not put
in the navigation bar, but the scan page was still included in
the footer causing invalid HTML because the aria-labeled-by
element was missing.

closes #36

For reasons unknown, each word of the menu name appears as an
individual class in the list of classes associated with the
menu item. These were being concatenated together with hyphens,
but could end up with class names like 'course-content' which
has a special CSS meaning. For now we just filter out all
classes that don't contain a hyphen or underscore.

Workaround for #37