device_set_fingerprint

[Steve Boyd]

I am starting to write my own program to download my dive computer using 
the libdivecomputer DLL.

I am a bit confused about exactly what the device_set_fingerprint 
function does.  The documentation suggests that it has something to do 
with limiting downloads to just new dives, but it is unclear about 
exactly how it accomplishes that.

Any light you can shed on this is appreciated.