top-level index.html
run `npm install`, then `gulp` for a live reloading dev environment
adding enough columns to be sure when it virtualizes them
...I'm in it now.
Progress. cells and headers on screen for the first time.

## Function Rewrites

- [x] init (new dom element setup)
- [x] getHeadersWidth > calculateHeadersWidth
- [x] setHeadersWidth (new)
- [x] getCanvasWidth > calculateCanvasWidth
- [x] updateCanvasWidth (way lots of mucho changes)
- [x] getHeaderRowColumn (get from the left or right pane)
- [x] createColumnHeaders (put columns in left or right pane)
- [x] getViewportHeight > calculateHeights
- [x] calculateViewportWidth (new)
- [x] resizeCanvas
- [x] setPaneVisibility (new)
- [x] setScroller (new)
- [x] renderRows
- [x] appendRowHtml
- [x] removeRowFromCache