Pass the whole 'device_data_t' to the uemis downloader

Not only does it make it look more like the libdivecomputer downloaders,
but the uemis downloader needs it in order to support all the flags we
have.  Notably "download into private trip".

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Teach uemis downloader about downloading into private trips

Now that we pass in the full device_data_t information, we can look at
the "create_private_dive" flag and decide just how to record newly
downloaded dives properly.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Start sanitizing gaschange event information

Decode the gasmix data into a sane format when creating the event, and
add the (currently unused) ability to specify a gas change to a
particular cylinder rather than (or in addition to) the gasmix.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
WIP: suunto configure dive computer