add a hook so that selection-change event listener can be setup
in markup
Remove a11yclick's synthetic event types (ex: on(node, a11yclick.press, ...))

Just keep the part to emit synthetic "click" events for SPACE/ENTER
on a node whose ancestor has a d-keyboard-click attribute.

Fixes #192.
Setup dependency on jQuery.
Convert delite code to use jQuery DOM methods.
improve Scrollable.js:  .attr() is unnecessary