Unpun SingleSelect and Selectable events

[dznz]

Both SingleSelect and Selectable fire selected and deselected events, making event capture on a collection more difficult, as you get twice the events you want, with different parameters.

Update Selectable's selected and deselected events to provide the model as its first parameter (like how the collection selected event behaved previously).

Change SingleSelect to fire select:one and deselect:one events instead of the selected and deselected events. This is roughly similar to the namespacing of the MultiSelect and so maintains a foolish consistency.

Also:

• Update the tests
• Update the Readme documentation