Hack up some very rudimentary support for the Uemis xml format

Hack up some very rudimentary support for the Uemis xml format

I think I'll need to re-organize the handling of per-format code, but
for now we just mix it all up.

The uemis conversion is also questionable even for just the small parts
I do.  Does it really do "centiPSI"? That sounds crazy.  I'm waiting for
Dirk to send me some actual human-readable output from the dives, right
now some of it is just rough guesses.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>