- Removed inf/nan checking from PlotDataItem and PlotCurveItem; improved performance
- Added 'connect' option to PlotDataItem and PlotCurveItem to affect which line segments are drawn
- arrayToQPath() added 'finite' connection mode which omits non-finite values from connections
Merge branch 'plotdata-nan' into develop

- Removed inf/nan checking from PlotDataItem and PlotCurveItem; improved performance
- Added 'connect' option to PlotDataItem and PlotCurveItem to affect which line segments are drawn
- arrayToQPath() added 'finite' connection mode which omits non-finite values from connections