Add class daytimes column to lesson reg. It is no longer hidden in the
data column.
Datetime display has more formats.
Add last_login to user details page.
The user and lesson information are now saved to DOM elements. Current
user and lesson is set whenever an item with the user/lesson data
information is clicked. This eliminates the need of global arrays to track
the information.
My teaches and studies arrays are still kept. They are useful, for an
example to provide information to message recipient.
pagebeforeshow is not good unless the page can be reached only from one
entry point. Otherwise, the event fires everytime the page is flipped back
and forth.
Many click events for page transitions are now delegated by the document
itself. This change is in consistent with the reduced usage of
pagebeforeshow. However an issue with this approach is that the page could
be in an non-ready state when the transition finishes and flickers when
the click handler returns.