* set environment variables before starting QApp
* fix-422
* Better support of hidpi
* Fix Typo in App-Name
* Remove fontScaleFactor bits
* Add documenation for hidpi displays
* Added arrow symbols for the ScatterPlotItem
* Fixed arrows rotation in scatter plots
* Added new symbols to example
Co-authored-by: Miguel Sánchez de León Peque <msdeleonpeque@gmail.com>