Regard `startOfWeek` option in data grouping
Highstock: Fixed #3299 where Y axis labels on subsequent panes would be drawn outside the plot area when they should be inside like the first pane.
Fixed #3300 where data labels would remain semi-transparent when chart updated in the middle of labels fading in.
Merge pull request #3286 from tahajahangir/fix-startOfWeek-data-grouping

Regard `startOfWeek` option in data grouping
Fixed #3285, funnel and pyramid center option not working for vertical dimension.
Allow overriding Highcharts.numberFormat from the outside. Closes #3284.
Micro optimized
Fixed #3088, tooltip blocking new mouse interaction after hiding when useHTML is true.
Merge remote-tracking branch 'upstream/master'