Updated to v1.5.0

- Added `useSubPanel` option to enable the sub panal mode. Users can
generated extra elements to the under each of the normal appendGrid row.
Please notice that `useSubPanel` *is not compatible with* `rowDragging`
feature.
- Added `subPanelBuilder` and `subPanelGetter` callback function that
required for sub panel.
- Added `subPanel` option for `sectionClasses`.
- The long-awaited sub grid feature is available by make use of sub
panel!
- Added `rowCountName` option for changing the key name of row count
variable for the result of `getAllValue` method.
- Parameter order of `rowDataLoaded` method is changed.
- Performaced improve by changing the use of insertRow and insertCell
javascript function to appendChild.