[PATCH] Don't ignore actual diveable mixes

[Dirk Hohndel]

On Tue, Jun 10, 2014 at 11:00:01PM +0200, Anton Lundin wrote:
> Fist is really obvious. I quite regularly decompress using pure O2. Its
> as good last decompression gas as you get.
> 
> The second is a bit harder. There are quite few that dive with 80%+
> helium in there mixes but they exists, and there are real weirdos that
> dive heliox, so they are actual diveable gases too.

o2 == 1000 is of course valid. Silly.
he >= 800 means o2 <= 20. One could argue that there is a he level that is
not realistically useful, but then again (1/99) is life sustaining below
about 150m of depth.

So I'll take the patch after running the commit message through a
glance->English translator. :-)

/D