editable is now in charge of changing the style of the
cell under the cell editor.
The events fire from the cell editors are now more consistent.
Editable provides information for the cell editors to merge
into the event facade.
Scrollable has been simplyfied but doesn't quite work yet.
showEditor now receives a bunch of information (cellInfo)
to merge into the event facade of several events.
The properties 'visible' and 'hidden' were quite confusing
because they were not always the opposite of one another.
Now there is 'active' which tells whether the cell editor
is active or not, and 'visible' which  will usually go along
'active' but might be false if, for example, the cell
being edited scrolls out of the datatable window.
The names of several of those event facade properties
have been improved to better describe what they are.
There was a certain confusion in between stored values and
formatted values.  It worked, but the usage of the name
'value' for all of them in different circumstances made it hard
to be sure it did.
They reflect the changes done in the base files.