Prints out error properly if discharge geometry invalid

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Fixed bug with disc xy coords not being loaded into panel

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
better catching of when difference of starting angles is exactly pi radians

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Fixed some of the funny layout in the scroll geo inputs panel

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Finished the docs for the step-by-step

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>