Replace tree_expand_hidden.html with Intern unit test

This tests expansion of a parent row in a tree grid when it is not in
document flow.  Prior to 0.3.1, the children would expand but be rendered
with 0 height in browsers supporting CSS transitions.
Fix tree expand tests to fail when they should
Add RTL feature-detect to fix behavior in recent Chrome versions

WebKit used to universally keep scrollbars on the right side in RTL mode,
but Chrome now swaps the scrollbar to the left side like other browsers.
Safari (6, at least) still leaves it on the right.
CHANGES.md: Note RTL alignment fix
Update version of Dojo referenced in README
Update version for tag
Update version for dev towards next release
Fix #886: Add ColumnHider trigger node to domNode to always be visible

dgrid 0.3.14 introduced a regression where the trigger node to open the menu
would no longer appear on browsers with no/hidden scrollbars.  This resolves it
by adding the node as a direct child of the grid's domNode instead, so it is
always visible regardless.

Added support for an rtl query parameter to the ColumnHider test page.

Thanks @treasonx for the initial investigation on this.
Fix handling of RTL scrollbar behavior for IE11+
CHANGES.md: Note ColumnHider regression fix
Add Dijit TextBox editor tests to dgrid/editor functional test suite
Selection: Only emit dgrid-deselect event if previously selected

Also adds tests for select and deselect events;
original test cases courtesy of @treasonx.
CHANGES.md: Note Selection deselect event behavior fix
Fix #885: Escape column IDs in CSS selectors like we do grid IDs

Also avoid calling `put-selector/put` in areas sensitive to this for grid IDs,
as it currently can't handle some characters and doesn't understand escaping.

Special characters in column IDs are replaced with hyphens rather than escaped -
Grid already behaved this way, but updates were necessary to extensions
for consistency.
Add tests for escaping grid/column IDs where necessary
CHANGES.md: Note changes involving special chars in column IDs
Fix #822: Don't modify the selection when clicking on disabled rows
CHANGES.md: Note Selection behavior fix for disabled rows
demos: Move JS into modules
demos: Move DOM into modules