gscreen -fix plot not being reloaded after an origin change.

So after the plot would be offset from the tool movement
gscreen config -have the edit button change text

so one knows when one is in and out of edit mode.
gscreen -optionally get the preference file path from the INI

so one can have separate preference files for multiple configs with Gscreen ,
on one computer
gladevcp -fix apply button not applying
Adding the "flash" command to setsserial to allow updating of sserial remote firmware

Signed-off-by: Andy Pugh <andy@bodgesoc.org>