#9 Weather measurement limit checks not robust

[Rick Mach]

In TropModel.cpp/hpp, in most of the c'tors for the
trop classes, there's repeated phrase checking the
values of T, P and H. Our problems :

1). The check is copy/pasted. At least put it in one
function.
2) One of the checks is over-conservative. It is
possible to get humidity greater than 100% (perhaps up
to 103% when it is raining or snowing).