Updates to support new look and feel
Style fixes

* Fix demo grid style when DND is enabled
* Adjust config pane label widths so the Editor config pane's
  dismissOnEnter label fits without wrapping.
Fix column definition ordering

Use an array to define the columns if any of the field names are numeric.
Builder cleanup and fixes

* Tighten a few styles
* Fix some startup/destroy logic
* Move feature grid tooltips to right side and use enter/leave not over/out
* Remove Selection from feature grids as the handler was causing problems,
  and Selection wasn't used there to begin with
* Set doLayout: false on StackContainer so it doesn't try to set heights
* Use native DOM methods, not dom-attr
* Fix Docs link