[winswitch] start-desktop with Fedora KDE Plasma

[Bob Babcock]

[I sent this before with a messed up address, trying again]

I've been trying out xpra start-desktop with Windows 7 or 10 viewing Fedora 31.  
A few things I've had to figure out that don't seem well documented:

To start KDE Plasma, the option is --start=startkde, not --start=plasma as I 
first guessed

I must use the documented --start="xrandr..." option or the screen size is too 
large.  It doesn't default to 1920x1080.

I got multiple messages "Error Authentication is required to create a color 
managed device", fixed by workaround I found at
https://www.seei.biz/authentication-is-required-to-create-a-color-managed-device-in-xrdp/ 


I still get one message "System policy prevents control of network connections" 
but I can cancel or enter a password to get past this.

The first problem I don't know how to fix is that when I close a desktop 
application, the screen usually doesn't refresh.  Konsole behaves this way.  I 
see this both at home with nVidia video on the Linux side and on a PowerEdge 
server at work with matrox video and no working GUI (which is why I'm looking at 
start-desktop).

The second problem is that when I log off, I'm left with a black window which I 
can close, but the xpra server doesn't exit on the Linux side.  If I use 
--exit-with-children, the session doesn't even start.  Or maybe it starts but 
quits after xrandr?

On the Linux end, I do not have the beta repository enabled, so the xpra version 
is v3.0.2-r24387.
On the Windows end, I have 4.0.0.24461.