delite/Selection: quick doc fix
Selection.md: a few doc fixes
The parameter of the fetch method is now the tracked collection. Removal
of the postProcessStore method, and renaming of preProcessStore into
processQueryResult.
Simplify Viewport code and remove dojo/window dependency.
remove unused dependency
Fix problems reported by jshint.
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.
Update delite/Store user documentation

postProcessStore method does not exist anymore.
preProcessStore has been renamed processQueryResult.
Rewrite DialogUnderlay and add manual test.
It wasn't working at all before.
Also removes dojo/window and dojo/on dependencies.

It still needs a functional test, but perhaps that should be delayed until
the DialogLevelManager is ported too.

Fixes #201.