Change manual shortcut for screenshot to CTRL+D

To avoid conflicts with saving intensities (CTRL+S)

Signed-off-by: Nicola Ferralis <feranick@hotmail.com>
Do not enable save spots before running acquisition

Loading the locations saved before acquisition gives error.
Loading spot location routine needs work.

Signed-off-by: Nicola Ferralis <feranick@hotmail.com>