DRY up scattergl
DRY up scattergl

- use same convert routine for x and y errors,
- use same reset options object when initializing and resetting
  scene options.

etpinard/plotly.js,plotly/plotly.js,etpinard/plotly.js,plotly/plotly.js,etpinard/plotly.js,asolagmbh/plotly.js,asolagmbh/plotly.js,aburato/plotly.js,plotly/plotly.js,asolagmbh/plotly.js,aburato/plotly.js,plotly/plotly.js