Tree: Add dgrid-row-expanded class to expanded rows
Implement dgrid builder, providing a UI to explore features
Builder: ColumnGrid refactoring

* Don't extend ContentPane
* Use a dijit/form/Form for the add column controls
* Make the grid full-height
Builder: various cleanup
Builder: Fix DnD styles to show drop location
Builder: Size grids and textarea to fit
Builder: Fix remaining lint errors (and IE8)

* Change es3 to false to report trailing commas (which were breaking IE8)
* Ignore JS template in builder during linter runs
Builder: Style cleanup
Minor linting / code revisions
Builder: Update dstore listeners from remove to delete
Builder: Replace remote font-awesome with local icon font
Builder: FeatureGrid code tweaks
Builder: More CSS cleanup; make code textarea read-only
Builder: Replace onClose stub with close DOM event
Builder: Move store/array radios into FeatureGrid, refactor accordingly

Also fixed a couple of bugs in switch blocks, and removed a pub/sub topic
as part of the refactor
Builder: Leave out ColumnSet for now since we have no UI for it
Builder: Fix issues between store/array and dependent features
Builder: Fix display issues with feature grid and clean up more CSS
Builder: Minor code cleanup
Builder: Add expanding/collapsing About text