Much nicer implementation of uemis sample parsing - and add events, too

Much nicer implementation of uemis sample parsing - and add events, too

This is something I wanted to do for a while. Every uemis sample is simply
a packed structure with no padding. Instead of grabbing random bytes from
the middle of an unstructured data blob let's just define the structure
and access its members.

And while we do that, add support for the more useful uemis events as
well.

A couple of the warnings are disabled by default (compile time flag) as
they are just crazy - any normal dive will give you dozens and dozens of
speed warnings. Same goes for the PO2 green warning (I haven't looked but
this seems to trigger on a PO2 over 1.0 or something). Completely useless
and just hides actually useful info.

I still want to redo the way we visualize events in general - just
printing the text ontop of the profile really is suboptimal. Especially as
the uemis really seems to love to repeat several of the warnings quite
frequently.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>