Shearwater Predator timezone handling

[James Sarrett]

Hey all,

I've got a Shearwater Predator that I have just got to download logs
from, and it's great, except all the times seem to be incorrect.  It
looks like the computer has no idea about timezones/locations, so it
just uses whatever time it's set to.  It looks like libdivecomputer has
no idea either and so it assumes UTC.  For me in California, this means
all my dives are off by either 7 or 8 hours depending on DST.

I'm not sure what the right fix is, but it's definitely a problem.

-James

PS: I'm on xubuntu 13.04 amd64, using subsurface and libdivecomputer from apt.