Remove comma at end
Implement a chart option of a bubble chart for ships
Make a bubble chart for ships follow configurations on whether it has ticks

It is a bug that a bubble chart for ships cannot draw gridlines and minor gridlines, in the case of `chart.Ships.*.step` were not specified, whether or not `chart.Ships.*.gridlines` and `chart.Ships.*.minorGridlines` are specified.
Clarify that a chart option of a bubble chart is null
Separate out building intermediate object from building rows