Fix bug in supersensor

jsondata was deleted too soon, before
we'd finished using it.
Works using average climatology from image
Specify order of viewing angles in file

The viewing angles were being written to their
geotiff file in an arbitrary order. (It was the
same each time, but couldn't be determined from
looking at the code). Hardcode the order instead
so we can tell more easily what it is.
fixed error in gas transmission
Merge remote-tracking branch 'origin/master' into rayleigh
Works using per-pixel angle information