gui: bug fix in PlotCanvas
gui: only add one AR stream for all AR data

Even if they come from different acquisitions, it should be fine to merge them, as the only variant (for now) is the sample position.

We still have possibility to support separating into multiple streams later on if that makes sense (based on metadata like
e-beam spot size or voltage?)
gui: PointSelectOverlay bug fix *WIP*
Merge branch 'master' of 192.168.92.5:odemis
gui: Merge conflict resolved
gui: Final PointSelectOverlay fix
gui: disabled PointSelectOverlay debug string display
gui: removed interfering Freeze/Thaw pair in ViewController
driver: new driver for Omicron xX laser generators

very very basic untested code.
Merge branch 'master' of vpn.delmic.com:odemis
driver lle: some small clean ups