Fix problem with uncalled promise errback
Test page fixes

* Fix tree_expand to show first tree
* Fix init bug in test/Grid_headerless
* Update errorStores names to use 'fetch' instead of 'query'
* Make mayHaveChildren method more generic for hierarchical test stores
Add test for failing total promise in ODL#renderQuery
Replace ODL#_refreshDeferred with a promise chain
Fix tree to respect query start and count options

Also removed unnecessary Deferred.when calls
Update TODOs in _StoreMixin
Fix Rest_duplicates to actually test duplicates
CHANGES.md: Add notes accordingly based on recent changes