DM4 import change

[Dirk Hohndel]

Miika,

please look at the change that I committed to master. The existing DM4
import code was writing data directly into the dive that should go into
the first divecomputer instead. Can you test with the data that you have
that I got this right?

Also - DM4 doesn't store any meandepth data? Surprising.

Others with DM4 data, please test that the import is still correct...

Thanks

/D